Cargo.lock

@@ -2051,7 +2051,7 @@ dependencies = [
 
 [[package]]
 name = "image-api"
-version = "1.4.0"
+version = "1.5.0"
 dependencies = [
  "actix",
  "actix-cors",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "image-api"
-version = "1.4.0"
+version = "1.5.0"
 authors = ["Cameron Cordes <cameronc.dev@gmail.com>"]
 edition = "2024"
 

migrations/2026-08-25-000000_persona_chat_multi/down.sql

@@ -0,0 +1,32 @@
+-- Collapse back to one conversation per (user, persona). Where a persona has
+-- several, the most recently updated one wins and the rest are dropped —
+-- the v1 schema has nowhere to put them.
+
+CREATE TABLE persona_chat_conversations_old (
+    user_id INTEGER NOT NULL,
+    persona_id TEXT NOT NULL,
+    messages_json TEXT NOT NULL DEFAULT '[]',
+    turn_count INTEGER NOT NULL DEFAULT 0,
+    updated_at BIGINT NOT NULL,
+    PRIMARY KEY (user_id, persona_id)
+);
+
+INSERT INTO persona_chat_conversations_old (
+    user_id, persona_id, messages_json, turn_count, updated_at
+)
+SELECT user_id, persona_id, messages_json, turn_count, updated_at
+FROM persona_chat_conversations c
+WHERE c.updated_at = (
+    SELECT MAX(c2.updated_at)
+    FROM persona_chat_conversations c2
+    WHERE c2.user_id = c.user_id AND c2.persona_id = c.persona_id
+)
+GROUP BY user_id, persona_id;
+
+DROP INDEX IF EXISTS idx_persona_chat_updated;
+DROP INDEX IF EXISTS idx_persona_chat_persona;
+DROP TABLE persona_chat_conversations;
+ALTER TABLE persona_chat_conversations_old RENAME TO persona_chat_conversations;
+
+CREATE INDEX idx_persona_chat_updated
+    ON persona_chat_conversations (user_id, updated_at DESC);

migrations/2026-08-25-000000_persona_chat_multi/up.sql

@@ -0,0 +1,50 @@
+-- Multiple conversations per persona.
+--
+-- v1 keyed a transcript on (user_id, persona_id), so a persona had exactly
+-- one rolling conversation and there was no way to start a fresh topic
+-- without discarding the old one. The key is now an opaque `conversation_id`,
+-- with (user_id, persona_id) demoted to an index.
+--
+-- `title` is a short generated summary of the opening exchange, used as the
+-- conversation's name in the list. Empty until the first turn completes; the
+-- client falls back to the persona name while it is blank.
+--
+-- SQLite cannot redefine a primary key in place, so this is the standard
+-- create-copy-drop-rename dance. Existing transcripts carry over with a
+-- generated id and an empty title.
+
+CREATE TABLE persona_chat_conversations_new (
+    conversation_id TEXT NOT NULL PRIMARY KEY,
+    user_id INTEGER NOT NULL,
+    persona_id TEXT NOT NULL,
+    title TEXT NOT NULL DEFAULT '',
+    messages_json TEXT NOT NULL DEFAULT '[]',
+    turn_count INTEGER NOT NULL DEFAULT 0,
+    created_at BIGINT NOT NULL,
+    updated_at BIGINT NOT NULL
+);
+
+INSERT INTO persona_chat_conversations_new (
+    conversation_id, user_id, persona_id, title,
+    messages_json, turn_count, created_at, updated_at
+)
+SELECT
+    lower(hex(randomblob(16))),
+    user_id,
+    persona_id,
+    '',
+    messages_json,
+    turn_count,
+    updated_at,
+    updated_at
+FROM persona_chat_conversations;
+
+DROP INDEX IF EXISTS idx_persona_chat_updated;
+DROP TABLE persona_chat_conversations;
+ALTER TABLE persona_chat_conversations_new RENAME TO persona_chat_conversations;
+
+CREATE INDEX idx_persona_chat_updated
+    ON persona_chat_conversations (user_id, updated_at DESC);
+
+CREATE INDEX idx_persona_chat_persona
+    ON persona_chat_conversations (user_id, persona_id);

src/ai/handlers.rs

@@ -2051,7 +2051,7 @@ pub(crate) async fn cancel_turn_impl(
     entry.set_terminal_status(crate::ai::turn_registry::TurnStatus::Cancelled);
     span.set_status(Status::Ok);
 
-HttpResponse::Ok().json(serde_json::json!({
+    HttpResponse::Ok().json(serde_json::json!({
         "cancelled": true
     }))
 }

src/ai/insight_chat.rs

@@ -30,11 +30,11 @@ pub const DEFAULT_MAX_ITERATIONS: usize = 6;
 const DEFAULT_NUM_CTX: i32 = 32768;
 /// Headroom reserved for the model's response, deducted from the context
 /// budget when deciding whether to truncate the replayed history.
-const RESPONSE_HEADROOM_TOKENS: usize = 2048;
+pub(crate) const RESPONSE_HEADROOM_TOKENS: usize = 2048;
 /// Cheap byte-to-token approximation used by the truncation pass. The real
 /// tokenization is model-specific; this avoids carrying tiktoken just for a
 /// soft bound.
-const BYTES_PER_TOKEN: usize = 4;
+pub(crate) const BYTES_PER_TOKEN: usize = 4;
 /// Flat token cost charged per inlined image in the truncation budget. A
 /// 1024px-longest-edge JPEG (see `load_image_as_base64`) costs vision models on
 /// the order of ~1.3K tokens. Crucially, the raw base64 (hundreds of KB of
@@ -335,6 +335,13 @@ impl InsightChatService {
         if truncated {
             span.set_attribute(KeyValue::new("history_truncated", true));
         }
+        // Everything in `messages` at this point is replayed history that is
+        // ALREADY in the tree; only what the turn appends past this mark
+        // becomes new nodes. Captured after the budget pass, not from
+        // `path.len()`: truncation drains from the middle, so `path.len()`
+        // over-counts and the slice below would either swallow the new user
+        // turn or panic on an out-of-range start index.
+        let history_len = messages.len();
 
         // 7. Append the new user turn.
         messages.push(ChatMessage::user(req.user_message.clone()));
@@ -461,8 +468,7 @@ impl InsightChatService {
         //    relying on store_insight to flip prior rows' is_current=false.
         // Append new messages (this turn's user + assistant exchanges) as
         // tree nodes chained from the previous active_leaf_id.
-        let path_len = path.len();
-        let new_messages = messages[path_len..].to_vec();
+        let new_messages = messages[history_len..].to_vec();
         let mut parent_id = Some(store.active_leaf_id);
         for msg in &new_messages {
             let new_id = store.append_node(parent_id, msg.clone());
@@ -942,7 +948,6 @@ impl InsightChatService {
         let path = store
             .path_to_leaf(store.active_leaf_id)
             .ok_or_else(|| anyhow!("active_leaf_id {} not found in tree", store.active_leaf_id))?;
-        let path_len = path.len();
         let mut messages: Vec<ChatMessage> = path.iter().map(|n| n.message.clone()).collect();
 
         let stored_backend = insight.backend.clone();
@@ -1003,6 +1008,10 @@ impl InsightChatService {
         if truncated {
             let _ = entry.push_event(ChatStreamEvent::Truncated).await;
         }
+        // See the note in `chat_turn`: the new-node boundary must be read
+        // after the budget pass, because truncation drains replayed history
+        // out of the middle of `messages`.
+        let history_len = messages.len();
 
         messages.push(ChatMessage::user(req.user_message.clone()));
 
@@ -1046,7 +1055,7 @@ impl InsightChatService {
         }
 
         // Append new messages as tree nodes.
-        let new_messages = messages[path_len..].to_vec();
+        let new_messages = messages[history_len..].to_vec();
         let mut parent_id = Some(store.active_leaf_id);
         for msg in &new_messages {
             let new_id = store.append_node(parent_id, msg.clone());
@@ -2219,7 +2228,7 @@ pub fn env_max_iterations() -> usize {
 /// Read AGENTIC_CHAT_DEFAULT_NUM_CTX once per call — the assumed context
 /// window for the truncation budget when the request omits `num_ctx`. Same
 /// no-static-global rationale as `env_max_iterations` above.
-fn env_default_num_ctx() -> i32 {
+pub(crate) fn env_default_num_ctx() -> i32 {
     std::env::var("AGENTIC_CHAT_DEFAULT_NUM_CTX")
         .ok()
         .and_then(|s| s.parse::<i32>().ok())
@@ -2534,7 +2543,7 @@ pub struct ForkInfo {
 /// tool-dispatch assistant (empty content + tool_calls) is still attributed to
 /// the next rendered message. Detecting forks only on rendered nodes would miss
 /// regenerations where the model replied with a tool call.
-fn render_tree_path(
+pub(crate) fn render_tree_path(
     store: &ChatHistoryStore,
     path: &[&StoredChatNode],
 ) -> (Vec<RenderedMessage>, usize, Vec<u64>, Vec<Option<ForkInfo>>) {

src/ai/llm_client.rs

@@ -407,8 +407,8 @@ impl ChatHistoryStore {
             .collect()
     }
 
-    /// The parent of the given node, if any. Test-only helper.
-    #[cfg(test)]
+    /// The parent of the given node, if any. Used to re-anchor a rewind
+    /// that discards every rendered message onto the seed node above them.
     pub fn parent_of(&self, node_id: u64) -> Option<&StoredChatNode> {
         let node = self.nodes.iter().find(|n| n.id == node_id)?;
         let parent_id = node.parent_id?;

src/ai/mod.rs

@@ -7,13 +7,13 @@ pub mod gpu;
 pub mod handlers;
 pub mod insight_chat;
 pub mod insight_generator;
-pub mod persona_chat;
 pub mod llamacpp;
 pub mod llm_client;
 pub mod local_llm;
 pub mod nl_query;
 pub mod ollama;
 pub mod openrouter;
+pub mod persona_chat;
 pub mod pronunciation;
 pub mod sms_client;
 pub mod tts;
@@ -33,16 +33,18 @@ pub use handlers::{
     get_available_models_handler, get_insight_handler, get_insight_history_handler,
     get_openrouter_models_handler, rate_insight_handler, turn_async_handler, turn_replay_handler,
 };
-pub use persona_chat::{
-    persona_chat_history_handler, persona_chat_reset_handler, persona_chat_turn_handler,
-    persona_turn_cancel_handler, persona_turn_replay_handler,
-};
 pub use insight_generator::InsightGenerator;
 pub use llamacpp::LlamaCppClient;
 #[allow(unused_imports)]
 pub use llm_client::{
     ChatMessage, LlmClient, ModelCapabilities, Tool, ToolCall, ToolCallFunction, ToolFunction,
 };
+pub use persona_chat::{
+    persona_chat_branches_handler, persona_chat_conversations_handler,
+    persona_chat_create_conversation_handler, persona_chat_delete_conversation_handler,
+    persona_chat_history_handler, persona_chat_rewind_handler, persona_chat_switch_branch_handler,
+    persona_chat_turn_handler, persona_turn_cancel_handler, persona_turn_replay_handler,
+};
 // LocalLlm is constructed by binaries (reembed_embeddings, importers), not the server
 #[allow(unused_imports)]
 pub use local_llm::LocalLlm;

src/database/persona_dao.rs

@@ -13,16 +13,48 @@ use crate::otel::trace_db_call;
 /// One row of the persona-chat transcript. Lives in
 /// `persona_chat_conversations` (one row per `(user_id, persona_id)`).
 ///
-/// `turn_count` is the number of new turn-rows since the last persisted
-/// slice — used by the SSE `done` event for stats dashboards. The actual
-/// transcript is the `messages_json` blob.
+/// One persona conversation.
+///
+/// `turn_count` is the cumulative number of assistant turns on the active
+/// branch — what the list screen shows as the length of a conversation. The
+/// transcript itself is the `messages_json` blob, holding a serialized
+/// `ChatHistoryStore` tree. `title` is a generated summary of the opening
+/// exchange, empty until the first turn completes.
 #[derive(Clone, Debug)]
 pub struct PersonaChatRow {
+    pub conversation_id: String,
+    pub persona_id: String,
+    pub title: String,
     pub messages_json: String,
     pub turn_count: i32,
+    pub created_at: i64,
     pub updated_at: i64,
 }
 
+/// Column tuple → `PersonaChatRow`. Shared by the single-row and list
+/// queries so their `select(...)` orders can never drift apart.
+fn persona_chat_row(
+    (conversation_id, persona_id, title, messages_json, turn_count, created_at, updated_at): (
+        String,
+        String,
+        String,
+        String,
+        i32,
+        i64,
+        i64,
+    ),
+) -> PersonaChatRow {
+    PersonaChatRow {
+        conversation_id,
+        persona_id,
+        title,
+        messages_json,
+        turn_count,
+        created_at,
+        updated_at,
+    }
+}
+
 /// Patch shape for update_persona. None = leave field alone. Built-ins are
 /// allowed to flip `include_all_memories` but should reject name/prompt
 /// edits at the handler layer (built-in copy lives in the migration).
@@ -96,39 +128,72 @@ pub trait PersonaDao: Sync + Send {
 
     // ── Persona-chat (open chat with persona) persistence ───────────
     //
-    // Keyed by `(user_id, persona_id)` with a single rolling transcript
-    // per pair. No tree branching in v1 — matches the locked-in scope.
+    // Keyed on an opaque `conversation_id` so one persona can hold several
+    // separate conversations. `user_id` is checked on every read and write:
+    // the id is a bearer token for a transcript, so ownership can never be
+    // assumed from the id alone.
 
-    /// Fetch the rolling transcript for one `(user, persona)`. None when
-    /// the user has never started a conversation with this persona.
+    /// Fetch one conversation. None when it doesn't exist or belongs to
+    /// another user — the two are deliberately indistinguishable to callers.
     fn get_persona_chat(
         &mut self,
         cx: &opentelemetry::Context,
         user_id: i32,
-        persona_id: &str,
+        conversation_id: &str,
     ) -> Result<Option<PersonaChatRow>, DbError>;
 
-    /// Upsert (create-or-replace) the rolling transcript. Called once per
-    /// completed turn with the full new `messages_json`. The `turn_count`
-    /// is the number of user/assistant pairs added in this write.
-    fn upsert_persona_chat(
+    /// Every conversation this user has going, newest first. Backs the chat
+    /// list screen, so it returns the transcript blob too — the snippet is
+    /// derived from the tree rather than denormalized into its own column.
+    fn list_persona_chats(
+        &mut self,
+        cx: &opentelemetry::Context,
+        user_id: i32,
+    ) -> Result<Vec<PersonaChatRow>, DbError>;
+
+    /// Start a new conversation with a persona, returning its id. Several
+    /// conversations with the same persona are expected, so this never
+    /// reuses an existing row.
+    fn create_persona_chat(
         &mut self,
         cx: &opentelemetry::Context,
         user_id: i32,
         persona_id: &str,
+        created_at: i64,
+    ) -> Result<String, DbError>;
+
+    /// Replace a conversation's transcript. Called once per completed turn
+    /// with the full new `messages_json`; `turn_count` is the cumulative
+    /// assistant-turn count on the resulting active branch. Returns the
+    /// number of rows written — 0 means the conversation is gone or is not
+    /// this user's.
+    fn update_persona_chat(
+        &mut self,
+        cx: &opentelemetry::Context,
+        user_id: i32,
+        conversation_id: &str,
         messages_json: &str,
         turn_count: i32,
         updated_at: i64,
-    ) -> Result<(), DbError>;
+    ) -> Result<usize, DbError>;
 
-    /// Wipe the rolling transcript. Reserved for a future "New
-    /// conversation" affordance; the row itself stays (so a subsequent
-    /// get returns None, not 404).
-    fn clear_persona_chat(
+    /// Name a conversation. Written once, after the first turn produces
+    /// enough of an exchange to summarize.
+    fn set_persona_chat_title(
         &mut self,
         cx: &opentelemetry::Context,
         user_id: i32,
-        persona_id: &str,
+        conversation_id: &str,
+        title: &str,
+    ) -> Result<(), DbError>;
+
+    /// Delete a conversation outright. Backs both the list screen's delete
+    /// affordance and the reset endpoint.
+    fn delete_persona_chat(
+        &mut self,
+        cx: &opentelemetry::Context,
+        user_id: i32,
+        conversation_id: &str,
     ) -> Result<(), DbError>;
 }
 
@@ -351,84 +416,155 @@ impl PersonaDao for SqlitePersonaDao {
         &mut self,
         cx: &opentelemetry::Context,
         uid: i32,
-        pid: &str,
+        cid: &str,
     ) -> Result<Option<PersonaChatRow>, DbError> {
         trace_db_call(cx, "query", "get_persona_chat", |_span| {
             use schema::persona_chat_conversations::dsl::*;
             let mut conn = self.connection.lock().expect("PersonaDao lock");
             persona_chat_conversations
+                .filter(conversation_id.eq(cid))
+                // Scoped by user as well as id: the id is a bearer token for
+                // someone's transcript, so it never grants access on its own.
                 .filter(user_id.eq(uid))
-                .filter(persona_id.eq(pid))
-                .select((messages_json, turn_count, updated_at))
-                .first::<(String, i32, i64)>(conn.deref_mut())
+                .select((
+                    conversation_id,
+                    persona_id,
+                    title,
+                    messages_json,
+                    turn_count,
+                    created_at,
+                    updated_at,
+                ))
+                .first::<(String, String, String, String, i32, i64, i64)>(conn.deref_mut())
                 .optional()
-                .map(|opt| {
-                    opt.map(|(m, t, u)| PersonaChatRow {
-                        messages_json: m,
-                        turn_count: t,
-                        updated_at: u,
-                    })
-                })
+                .map(|opt| opt.map(persona_chat_row))
                 .map_err(|e| anyhow::anyhow!("Query error: {}", e))
         })
         .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
     }
 
-    fn upsert_persona_chat(
+    fn list_persona_chats(
+        &mut self,
+        cx: &opentelemetry::Context,
+        uid: i32,
+    ) -> Result<Vec<PersonaChatRow>, DbError> {
+        trace_db_call(cx, "query", "list_persona_chats", |_span| {
+            use schema::persona_chat_conversations::dsl::*;
+            let mut conn = self.connection.lock().expect("PersonaDao lock");
+            persona_chat_conversations
+                .filter(user_id.eq(uid))
+                .order(updated_at.desc())
+                .select((
+                    conversation_id,
+                    persona_id,
+                    title,
+                    messages_json,
+                    turn_count,
+                    created_at,
+                    updated_at,
+                ))
+                .load::<(String, String, String, String, i32, i64, i64)>(conn.deref_mut())
+                .map(|rows| rows.into_iter().map(persona_chat_row).collect())
+                .map_err(|e| anyhow::anyhow!("Query error: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn create_persona_chat(
         &mut self,
         cx: &opentelemetry::Context,
         uid: i32,
         pid: &str,
-        json: &str,
-        count: i32,
-        updated_at: i64,
-    ) -> Result<(), DbError> {
-        trace_db_call(cx, "upsert", "upsert_persona_chat", |_span| {
+        created: i64,
+    ) -> Result<String, DbError> {
+        trace_db_call(cx, "insert", "create_persona_chat", |_span| {
+            use schema::persona_chat_conversations::dsl::*;
             let mut conn = self.connection.lock().expect("PersonaDao lock");
-            // INSERT OR REPLACE on the (user_id, persona_id) PRIMARY KEY —
-            // single rolling transcript, so a new write always supersedes
-            // the prior one in full. The mobile hook serialises turns with
-            // a per-persona mutex, so this never races. Plain
-            // `sql_query` sidesteps a Diesel type-recursion blow-up that
-            // hits `insert_into(...).on_conflict(...).do_update().set(...)`
-            // with this many typed columns.
-            diesel::sql_query(
-                "INSERT INTO persona_chat_conversations \
-                 (user_id, persona_id, messages_json, turn_count, updated_at) \
-                 VALUES (?, ?, ?, ?, ?) \
-                 ON CONFLICT(user_id, persona_id) DO UPDATE SET \
-                 messages_json = excluded.messages_json, \
-                 turn_count = excluded.turn_count, \
-                 updated_at = excluded.updated_at",
-            )
-            .bind::<diesel::sql_types::Integer, _>(uid)
-            .bind::<diesel::sql_types::Text, _>(pid)
-            .bind::<diesel::sql_types::Text, _>(json)
-            .bind::<diesel::sql_types::Integer, _>(count)
-            .bind::<diesel::sql_types::BigInt, _>(updated_at)
-            .execute(conn.deref_mut())
-            .map_err(|e| anyhow::anyhow!("Upsert error: {}", e))?;
-            Ok(())
+            let new_id = uuid::Uuid::new_v4().to_string();
+            diesel::insert_into(persona_chat_conversations)
+                .values((
+                    conversation_id.eq(&new_id),
+                    user_id.eq(uid),
+                    persona_id.eq(pid),
+                    title.eq(""),
+                    // The empty tree; the first turn seeds it with the
+                    // persona's system prompt.
+                    messages_json.eq("[]"),
+                    turn_count.eq(0),
+                    created_at.eq(created),
+                    updated_at.eq(created),
+                ))
+                .execute(conn.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Insert error: {}", e))?;
+            Ok(new_id)
         })
         .map_err(|e| DbError::log(DbErrorKind::InsertError, e))
     }
 
-    fn clear_persona_chat(
+    fn update_persona_chat(
         &mut self,
         cx: &opentelemetry::Context,
         uid: i32,
-        pid: &str,
-    ) -> Result<(), DbError> {
-        trace_db_call(cx, "delete", "clear_persona_chat", |_span| {
+        cid: &str,
+        json: &str,
+        count: i32,
+        updated: i64,
+    ) -> Result<usize, DbError> {
+        trace_db_call(cx, "update", "update_persona_chat", |_span| {
+            use schema::persona_chat_conversations::dsl::*;
+            let mut conn = self.connection.lock().expect("PersonaDao lock");
+            diesel::update(
+                persona_chat_conversations
+                    .filter(conversation_id.eq(cid))
+                    .filter(user_id.eq(uid)),
+            )
+            .set((
+                messages_json.eq(json),
+                turn_count.eq(count),
+                updated_at.eq(updated),
+            ))
+            .execute(conn.deref_mut())
+            .map_err(|e| anyhow::anyhow!("Update error: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn set_persona_chat_title(
+        &mut self,
+        cx: &opentelemetry::Context,
+        uid: i32,
+        cid: &str,
+        new_title: &str,
+    ) -> Result<(), DbError> {
+        trace_db_call(cx, "update", "set_persona_chat_title", |_span| {
+            use schema::persona_chat_conversations::dsl::*;
+            let mut conn = self.connection.lock().expect("PersonaDao lock");
+            diesel::update(
+                persona_chat_conversations
+                    .filter(conversation_id.eq(cid))
+                    .filter(user_id.eq(uid)),
+            )
+            .set(title.eq(new_title))
+            .execute(conn.deref_mut())
+            .map_err(|e| anyhow::anyhow!("Update error: {}", e))?;
+            Ok(())
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn delete_persona_chat(
+        &mut self,
+        cx: &opentelemetry::Context,
+        uid: i32,
+        cid: &str,
+    ) -> Result<(), DbError> {
+        trace_db_call(cx, "delete", "delete_persona_chat", |_span| {
             use schema::persona_chat_conversations::dsl::*;
             let mut conn = self.connection.lock().expect("PersonaDao lock");
-            // Delete the row entirely so the next get returns None.
-            // The next send will INSERT a fresh seed (system + greeting)
-            // via the same code path a brand-new persona uses.
             diesel::delete(
                 persona_chat_conversations
-                    .filter(user_id.eq(uid))
-                    .filter(persona_id.eq(pid)),
+                    .filter(conversation_id.eq(cid))
+                    .filter(user_id.eq(uid)),
             )
             .execute(conn.deref_mut())
             .map_err(|e| anyhow::anyhow!("Delete error: {}", e))?;
@@ -437,7 +573,6 @@ impl PersonaDao for SqlitePersonaDao {
         .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
     }
 }
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -587,74 +722,170 @@ mod tests {
 
     // ── Persona-chat DAO tests ─────────────────────────────────────
 
-    #[test]
-    fn persona_chat_get_returns_none_for_never_started() {
-        let cx = opentelemetry::Context::new();
-        let (mut dao, uid) = dao_with_user("p1");
-        let row = dao.get_persona_chat(&cx, uid, "default").unwrap();
-        assert!(row.is_none());
+    /// Second user, for the isolation tests.
+    fn second_user(dao: &SqlitePersonaDao, username: &str) -> i32 {
+        use crate::database::schema::users::dsl as u;
+        let conn = dao.connection.clone();
+        diesel::insert_into(u::users)
+            .values((u::username.eq(username), u::password.eq("x")))
+            .execute(conn.lock().unwrap().deref_mut())
+            .unwrap();
+        u::users
+            .filter(u::username.eq(username))
+            .select(u::id)
+            .first(conn.lock().unwrap().deref_mut())
+            .unwrap()
     }
 
     #[test]
-    fn persona_chat_upsert_then_get_round_trip() {
+    fn persona_chat_get_returns_none_for_an_unknown_conversation() {
+        let cx = opentelemetry::Context::new();
+        let (mut dao, uid) = dao_with_user("p1");
+        assert!(
+            dao.get_persona_chat(&cx, uid, "no-such-id")
+                .unwrap()
+                .is_none()
+        );
+    }
+
+    #[test]
+    fn persona_chat_create_then_get_round_trip() {
         let cx = opentelemetry::Context::new();
         let (mut dao, uid) = dao_with_user("p2");
-        dao.upsert_persona_chat(&cx, uid, "journal", "[]", 1, 100)
-        .unwrap();
-        let row = dao.get_persona_chat(&cx, uid, "journal").unwrap().unwrap();
-        assert_eq!(row.messages_json, "[]");
-        assert_eq!(row.turn_count, 1);
+        let cid = dao.create_persona_chat(&cx, uid, "journal", 100).unwrap();
+
+        let row = dao.get_persona_chat(&cx, uid, &cid).unwrap().unwrap();
+        assert_eq!(row.conversation_id, cid);
+        assert_eq!(row.persona_id, "journal");
+        assert_eq!(row.title, "", "unnamed until the first turn completes");
+        assert_eq!(row.turn_count, 0);
+        assert_eq!(row.created_at, 100);
         assert_eq!(row.updated_at, 100);
     }
 
     #[test]
-    fn persona_chat_upsert_replaces_existing_row() {
+    fn persona_chat_create_makes_a_separate_row_each_time() {
+        // The whole point of the conversation_id key: one persona, several
+        // independent threads.
         let cx = opentelemetry::Context::new();
         let (mut dao, uid) = dao_with_user("p3");
-        dao.upsert_persona_chat(&cx, uid, "journal", "first", 1, 100).unwrap();
-        dao.upsert_persona_chat(&cx, uid, "journal", "second", 2, 200).unwrap();
-        let row = dao.get_persona_chat(&cx, uid, "journal").unwrap().unwrap();
+        let first = dao.create_persona_chat(&cx, uid, "journal", 100).unwrap();
+        let second = dao.create_persona_chat(&cx, uid, "journal", 200).unwrap();
+
+        assert_ne!(first, second);
+        assert_eq!(dao.list_persona_chats(&cx, uid).unwrap().len(), 2);
+    }
+
+    #[test]
+    fn persona_chat_update_replaces_the_transcript() {
+        let cx = opentelemetry::Context::new();
+        let (mut dao, uid) = dao_with_user("p4");
+        let cid = dao.create_persona_chat(&cx, uid, "journal", 100).unwrap();
+
+        let rows = dao
+            .update_persona_chat(&cx, uid, &cid, "first", 1, 150)
+            .unwrap();
+        assert_eq!(rows, 1);
+        let rows = dao
+            .update_persona_chat(&cx, uid, &cid, "second", 2, 200)
+            .unwrap();
+        assert_eq!(rows, 1);
+
+        let row = dao.get_persona_chat(&cx, uid, &cid).unwrap().unwrap();
         assert_eq!(row.messages_json, "second");
         assert_eq!(row.turn_count, 2);
         assert_eq!(row.updated_at, 200);
-        // Single rolling transcript → exactly one row per (user, persona).
+        assert_eq!(row.created_at, 100, "creation time is not disturbed");
     }
 
     #[test]
-    fn persona_chat_isolation_between_users() {
+    fn persona_chat_update_reports_zero_rows_for_an_unknown_conversation() {
+        // The turn loop treats 0 as "the conversation went away mid-turn"
+        // rather than silently succeeding.
         let cx = opentelemetry::Context::new();
-        let (mut dao, uid1) = dao_with_user("u1");
-        let uid2: i32 = {
-            let conn = dao.connection.clone();
-            use crate::database::schema::users::dsl as u;
-            diesel::insert_into(u::users)
-                .values((u::username.eq("u2"), u::password.eq("x")))
-                .execute(conn.lock().unwrap().deref_mut())
-                .unwrap();
-            u::users
-                .filter(u::username.eq("u2"))
-                .select(u::id)
-                .first(conn.lock().unwrap().deref_mut())
-                .unwrap()
-        };
-        dao.upsert_persona_chat(&cx, uid1, "default", "u1-row", 1, 1).unwrap();
-        dao.upsert_persona_chat(&cx, uid2, "default", "u2-row", 1, 2).unwrap();
+        let (mut dao, uid) = dao_with_user("p5");
+        let rows = dao
+            .update_persona_chat(&cx, uid, "no-such-id", "x", 1, 1)
+            .unwrap();
+        assert_eq!(rows, 0);
+    }
+
+    #[test]
+    fn persona_chat_set_title_names_the_conversation() {
+        let cx = opentelemetry::Context::new();
+        let (mut dao, uid) = dao_with_user("p6");
+        let cid = dao.create_persona_chat(&cx, uid, "journal", 100).unwrap();
+
+        dao.set_persona_chat_title(&cx, uid, &cid, "June recap")
+            .unwrap();
+        let row = dao.get_persona_chat(&cx, uid, &cid).unwrap().unwrap();
+        assert_eq!(row.title, "June recap");
+    }
+
+    #[test]
+    fn persona_chat_list_orders_newest_first() {
+        let cx = opentelemetry::Context::new();
+        let (mut dao, uid) = dao_with_user("p7");
+        let older = dao.create_persona_chat(&cx, uid, "journal", 100).unwrap();
+        let newer = dao.create_persona_chat(&cx, uid, "coach", 300).unwrap();
+        let middle = dao.create_persona_chat(&cx, uid, "default", 200).unwrap();
+
+        let ids: Vec<String> = dao
+            .list_persona_chats(&cx, uid)
+            .unwrap()
+            .into_iter()
+            .map(|r| r.conversation_id)
+            .collect();
         assert_eq!(
-            dao.get_persona_chat(&cx, uid1, "default").unwrap().unwrap().messages_json,
-            "u1-row"
-        );
-        assert_eq!(
-            dao.get_persona_chat(&cx, uid2, "default").unwrap().unwrap().messages_json,
-            "u2-row"
+            ids,
+            vec![newer, middle, older],
+            "ordered by updated_at descending so the list screen needs no re-sort"
         );
     }
 
     #[test]
-    fn persona_chat_clear_wipes_the_row_so_get_returns_none() {
+    fn persona_chat_list_is_empty_for_a_user_who_has_never_chatted() {
         let cx = opentelemetry::Context::new();
-        let (mut dao, uid) = dao_with_user("p4");
-        dao.upsert_persona_chat(&cx, uid, "default", "[]", 1, 1).unwrap();
-        dao.clear_persona_chat(&cx, uid, "default").unwrap();
-        assert!(dao.get_persona_chat(&cx, uid, "default").unwrap().is_none());
+        let (mut dao, uid) = dao_with_user("p8");
+        assert!(dao.list_persona_chats(&cx, uid).unwrap().is_empty());
+    }
+
+    #[test]
+    fn persona_chat_delete_removes_the_conversation() {
+        let cx = opentelemetry::Context::new();
+        let (mut dao, uid) = dao_with_user("p9");
+        let cid = dao.create_persona_chat(&cx, uid, "journal", 100).unwrap();
+
+        dao.delete_persona_chat(&cx, uid, &cid).unwrap();
+        assert!(dao.get_persona_chat(&cx, uid, &cid).unwrap().is_none());
+        assert!(dao.list_persona_chats(&cx, uid).unwrap().is_empty());
+    }
+
+    #[test]
+    fn persona_chat_reads_and_writes_are_scoped_to_the_owner() {
+        // A conversation_id is a bearer token for someone's transcript, so
+        // holding one must not grant another user access to it.
+        let cx = opentelemetry::Context::new();
+        let (mut dao, uid1) = dao_with_user("owner");
+        let uid2 = second_user(&dao, "intruder");
+        let cid = dao.create_persona_chat(&cx, uid1, "journal", 100).unwrap();
+        dao.update_persona_chat(&cx, uid1, &cid, "private", 1, 100)
+            .unwrap();
+
+        assert!(
+            dao.get_persona_chat(&cx, uid2, &cid).unwrap().is_none(),
+            "another user cannot read it"
+        );
+        assert_eq!(
+            dao.update_persona_chat(&cx, uid2, &cid, "tampered", 9, 999)
+                .unwrap(),
+            0,
+            "another user cannot write it"
+        );
+        dao.delete_persona_chat(&cx, uid2, &cid).unwrap();
+
+        let row = dao.get_persona_chat(&cx, uid1, &cid).unwrap().unwrap();
+        assert_eq!(row.messages_json, "private", "and cannot delete it");
+        assert!(dao.list_persona_chats(&cx, uid2).unwrap().is_empty());
     }
 }

src/database/schema.rs

@@ -172,11 +172,14 @@ diesel::table! {
 }
 
 diesel::table! {
-    persona_chat_conversations (user_id, persona_id) {
+    persona_chat_conversations (conversation_id) {
+        conversation_id -> Text,
         user_id -> Integer,
         persona_id -> Text,
+        title -> Text,
         messages_json -> Text,
         turn_count -> Integer,
+        created_at -> BigInt,
         updated_at -> BigInt,
     }
 }

src/main.rs

@@ -384,9 +384,14 @@ fn main() -> std::io::Result<()> {
                 .service(ai::cancel_turn_handler)
                 .service(ai::persona_chat_history_handler)
                 .service(ai::persona_chat_turn_handler)
-                .service(ai::persona_chat_reset_handler)
+                .service(ai::persona_chat_create_conversation_handler)
+                .service(ai::persona_chat_delete_conversation_handler)
                 .service(ai::persona_turn_replay_handler)
                 .service(ai::persona_turn_cancel_handler)
+                .service(ai::persona_chat_rewind_handler)
+                .service(ai::persona_chat_switch_branch_handler)
+                .service(ai::persona_chat_branches_handler)
+                .service(ai::persona_chat_conversations_handler)
                 .service(ai::rate_insight_handler)
                 .service(ai::export_training_data_handler)
                 .service(ai::tts_speech_handler)

src/thumbnails.rs

@@ -175,11 +175,7 @@ fn encode_large_jpeg(img: image::DynamicImage, dest: &Path) -> std::io::Result<(
 /// ffmpeg path for HEIC/HEIF (image crate can't decode these). Mirrors
 /// [`crate::video::actors::generate_image_thumbnail_ffmpeg`] but scales
 /// to the large-preview cap instead of 200.
-fn generate_large_preview_ffmpeg(
-    src: &Path,
-    dest: &Path,
-    orientation: i32,
-) -> std::io::Result<()> {
+fn generate_large_preview_ffmpeg(src: &Path, dest: &Path, orientation: i32) -> std::io::Result<()> {
     // Rotation + scale + colorspace. HEIC sources use Display P3; without
     // colorspace=bt709 the mjpeg encoder treats P3 values as sRGB, producing
     // warm/oversaturated output. The min(iw,cap) trick caps the long edge