feat: nightly agentic pre-generation of memory reels

Implement end-to-end nightly pre-generation of memory reels with agentic
scripting that grounds narration in calendar, location, messages, and RAG.

Sections A-E from the plan:

A. Extract produce_reel pipeline core from run_reel_job with
   ScripterMode::Fast/Agentic and progress callbacks.

B. Agentic scripter: factor run_readonly_tool_loop from the insight
   generator, build read-only tool gate, prompt builder with GPS, and
   generate_script_agentic with fallback to fast path.

C. Precomputed reels ledger (SQLite table + DAO), GET /reels/precomputed
   handler with validity gate, GET /reels/by-key/{key}/video streaming,
   and normalize_library_key helper.

D. Nightly scheduler: spawn_pregen_scheduler with configurable hour,
   run_pregen_batch (day/week/month spans), pregen_one with dedup and
   disk-check, secs_until_next_run_hour time math.

E. user_ai_prefs passive mirror table + DAO for param capture in
   create_reel_handler and replay in the scheduler.

Also fixes resolve_library_param signature to take &[Library] and adds
resolve_library_param_state wrapper for AppState callers.

New files: migrations/2026-06-13-000000_add_precomputed_reels/,
  migrations/2026-06-13-000010_add_user_ai_prefs/,
  src/database/precomputed_reel_dao.rs,
  src/database/user_ai_prefs_dao.rs

src/database/precomputed_reel_dao.rs

@@ -0,0 +1,321 @@
+use diesel::prelude::*;
+use diesel::sqlite::SqliteConnection;
+use std::ops::DerefMut;
+use std::sync::{Arc, Mutex};
+
+use crate::database::models::{InsertablePrecomputedReel, PrecomputedReel};
+use crate::database::schema;
+use crate::database::{DbError, DbErrorKind, connect};
+use crate::otel::trace_db_call;
+
+/// Ledger for precomputed memory reels. The nightly agentic job writes a
+/// row after each successful render; the `GET /reels/precomputed` handler
+/// reads it to gate on freshness and serve the cached MP4.
+pub trait PrecomputedReelDao: Sync + Send {
+    /// Insert a precomputed reel row. Returns the new row's id.
+    /// Written by the nightly agentic job (Section D).
+    #[allow(dead_code)]
+    fn record_reel(
+        &mut self,
+        context: &opentelemetry::Context,
+        row: &InsertablePrecomputedReel,
+    ) -> Result<i32, DbError>;
+
+    /// Find the latest precomputed reel for the given (span, library_key).
+    fn latest_for(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+    ) -> Result<Option<PrecomputedReel>, DbError>;
+
+    /// Return true when a fresh precomputed reel exists for the given
+    /// (span, library_key, render_version) that was generated at or after
+    /// `min_generated_at`. Used as a fast existence gate before falling
+    /// back to `latest_for` (avoids a second query path).
+    fn exists_fresh(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+        render_version: i32,
+        min_generated_at: i64,
+    ) -> Result<bool, DbError>;
+}
+
+pub struct SqlitePrecomputedReelDao {
+    connection: Arc<Mutex<SqliteConnection>>,
+}
+
+impl Default for SqlitePrecomputedReelDao {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl SqlitePrecomputedReelDao {
+    pub fn new() -> Self {
+        Self {
+            connection: Arc::new(Mutex::new(connect())),
+        }
+    }
+
+    #[cfg(test)]
+    pub fn from_connection(conn: Arc<Mutex<SqliteConnection>>) -> Self {
+        Self { connection: conn }
+    }
+}
+
+impl PrecomputedReelDao for SqlitePrecomputedReelDao {
+    fn record_reel(
+        &mut self,
+        context: &opentelemetry::Context,
+        row: &InsertablePrecomputedReel,
+    ) -> Result<i32, DbError> {
+        trace_db_call(context, "insert", "record_reel", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            diesel::insert_into(dsl::precomputed_reels)
+                .values(row)
+                .execute(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to insert reel: {}", e))?;
+
+            dsl::precomputed_reels
+                .order(dsl::id.desc())
+                .select(dsl::id)
+                .first::<i32>(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to get reel id: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::InsertError, e))
+    }
+
+    fn latest_for(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+    ) -> Result<Option<PrecomputedReel>, DbError> {
+        trace_db_call(context, "query", "latest_for", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            dsl::precomputed_reels
+                .filter(dsl::span.eq(span))
+                .filter(dsl::library_key.eq(library_key))
+                .order(dsl::generated_at.desc())
+                .first::<PrecomputedReel>(connection.deref_mut())
+                .optional()
+                .map_err(|e| anyhow::anyhow!("Failed to get latest reel: {}", e))
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+
+    fn exists_fresh(
+        &mut self,
+        context: &opentelemetry::Context,
+        span: &str,
+        library_key: &str,
+        render_version: i32,
+        min_generated_at: i64,
+    ) -> Result<bool, DbError> {
+        trace_db_call(context, "query", "exists_fresh", |_span| {
+            use schema::precomputed_reels::dsl;
+
+            let mut connection = self
+                .connection
+                .lock()
+                .expect("Unable to lock PrecomputedReelDao");
+
+            let count: i64 = dsl::precomputed_reels
+                .filter(dsl::span.eq(span))
+                .filter(dsl::library_key.eq(library_key))
+                .filter(dsl::render_version.eq(render_version))
+                .filter(dsl::generated_at.ge(min_generated_at))
+                .count()
+                .get_result(connection.deref_mut())
+                .map_err(|e| anyhow::anyhow!("Failed to check fresh reel: {}", e))?;
+
+            Ok(count > 0)
+        })
+        .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use diesel::Connection;
+    use diesel_migrations::{EmbeddedMigrations, MigrationHarness, embed_migrations};
+
+    const DB_MIGRATIONS: EmbeddedMigrations = embed_migrations!();
+
+    fn setup_dao() -> SqlitePrecomputedReelDao {
+        let mut conn = SqliteConnection::establish(":memory:")
+            .expect("Unable to create in-memory db connection");
+        conn.run_pending_migrations(DB_MIGRATIONS)
+            .expect("Failure running DB migrations");
+        SqlitePrecomputedReelDao::from_connection(Arc::new(Mutex::new(conn)))
+    }
+
+    fn ctx() -> opentelemetry::Context {
+        opentelemetry::Context::new()
+    }
+
+    fn sample_row() -> InsertablePrecomputedReel {
+        InsertablePrecomputedReel {
+            span: "day".to_string(),
+            library_key: "1".to_string(),
+            cache_key: "abc123".to_string(),
+            output_path: "/tmp/reel.mp4".to_string(),
+            title: "Test Reel".to_string(),
+            media_count: 10,
+            render_version: 1,
+            tz_offset_minutes: 0,
+            voice: Some("default".to_string()),
+            generated_at: 1_000_000,
+        }
+    }
+
+    #[test]
+    fn record_reel_inserts_and_returns_id() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+        let row = sample_row();
+
+        let id = dao.record_reel(&ctx, &row).unwrap();
+        assert!(id > 0, "should return a positive id");
+    }
+
+    #[test]
+    fn record_reel_returns_increasing_ids() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+        let row = sample_row();
+
+        let id1 = dao.record_reel(&ctx, &row).unwrap();
+        let id2 = dao.record_reel(&ctx, &row).unwrap();
+        assert!(id2 > id1, "each insert should get a higher id");
+    }
+
+    #[test]
+    fn latest_for_returns_latest() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let row1 = InsertablePrecomputedReel {
+            generated_at: 1_000_000,
+            ..sample_row()
+        };
+        let row2 = InsertablePrecomputedReel {
+            generated_at: 2_000_000,
+            ..sample_row()
+        };
+
+        dao.record_reel(&ctx, &row1).unwrap();
+        dao.record_reel(&ctx, &row2).unwrap();
+
+        let latest = dao.latest_for(&ctx, "day", "1").unwrap().unwrap();
+        assert_eq!(latest.generated_at, 2_000_000);
+    }
+
+    #[test]
+    fn latest_for_scoped_by_span_and_library() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let day_row = InsertablePrecomputedReel {
+            span: "day".to_string(),
+            library_key: "1".to_string(),
+            generated_at: 1_000_000,
+            ..sample_row()
+        };
+        let week_row = InsertablePrecomputedReel {
+            span: "week".to_string(),
+            library_key: "1".to_string(),
+            generated_at: 2_000_000,
+            ..sample_row()
+        };
+
+        dao.record_reel(&ctx, &day_row).unwrap();
+        dao.record_reel(&ctx, &week_row).unwrap();
+
+        let day_latest = dao.latest_for(&ctx, "day", "1").unwrap().unwrap();
+        assert_eq!(day_latest.span, "day");
+
+        let week_latest = dao.latest_for(&ctx, "week", "1").unwrap().unwrap();
+        assert_eq!(week_latest.span, "week");
+
+        // Different library returns None
+        let missing = dao.latest_for(&ctx, "day", "99").unwrap();
+        assert!(missing.is_none());
+    }
+
+    #[test]
+    fn latest_for_returns_none_when_no_rows() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let result = dao.latest_for(&ctx, "day", "1").unwrap();
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn exists_fresh_returns_true_when_present() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        dao.record_reel(&ctx, &sample_row()).unwrap();
+
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 900_000).unwrap();
+        assert!(exists, "should find the row we just inserted");
+    }
+
+    #[test]
+    fn exists_fresh_returns_false_when_missing() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 900_000).unwrap();
+        assert!(!exists, "should not find anything in empty table");
+    }
+
+    #[test]
+    fn exists_fresh_respects_min_generated_at() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        dao.record_reel(&ctx, &sample_row()).unwrap();
+
+        // Below the threshold — should exist
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 500_000).unwrap();
+        assert!(exists);
+
+        // Above the threshold — should not exist
+        let exists = dao.exists_fresh(&ctx, "day", "1", 1, 2_000_000).unwrap();
+        assert!(!exists);
+    }
+
+    #[test]
+    fn exists_fresh_respects_render_version() {
+        let mut dao = setup_dao();
+        let ctx = ctx();
+
+        let row_v1 = InsertablePrecomputedReel {
+            render_version: 1,
+            ..sample_row()
+        };
+        dao.record_reel(&ctx, &row_v1).unwrap();
+
+        assert!(dao.exists_fresh(&ctx, "day", "1", 1, 900_000).unwrap());
+        assert!(!dao.exists_fresh(&ctx, "day", "1", 2, 900_000).unwrap());
+    }
+}