feat: multi-library foundation (schema + libraries module)

Adds a `libraries` registry table and threads library_id through
per-instance metadata tables (image_exif, photo_insights,
entity_photo_links, video_preview_clips). File-path columns renamed to
rel_path to make the relative-to-root semantics explicit. Adds
content_hash + size_bytes on image_exif to support future hash-keyed
thumbnail/HLS dedup. Tags and favorites stay library-agnostic so they
share across libraries by rel_path.

Behavior is unchanged: a single primary library (id=1) is seeded from
BASE_PATH on first boot; all handlers and DAOs route through it as a
transitional shim until the API gains a library query param.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/state.rs

@@ -3,8 +3,10 @@ use crate::database::{
     CalendarEventDao, DailySummaryDao, ExifDao, InsightDao, KnowledgeDao, LocationHistoryDao,
     SearchHistoryDao, SqliteCalendarEventDao, SqliteDailySummaryDao, SqliteExifDao,
     SqliteInsightDao, SqliteKnowledgeDao, SqliteLocationHistoryDao, SqliteSearchHistoryDao,
+    connect,
 };
 use crate::database::{PreviewDao, SqlitePreviewDao};
+use crate::libraries::{self, Library};
 use crate::tags::{SqliteTagDao, TagDao};
 use crate::video::actors::{
     PlaylistGenerator, PreviewClipGenerator, StreamActor, VideoPlaylistManager,
@@ -17,6 +19,11 @@ pub struct AppState {
     pub stream_manager: Arc<Addr<StreamActor>>,
     pub playlist_manager: Arc<Addr<VideoPlaylistManager>>,
     pub preview_clip_generator: Arc<Addr<PreviewClipGenerator>>,
+    /// All configured media libraries. Ordered by `id` ascending; the first
+    /// entry is the primary library.
+    pub libraries: Vec<Library>,
+    /// Legacy shim equal to `libraries[0].root_path`. Phase 2 transitional —
+    /// new code should go through `primary_library()`.
     pub base_path: String,
     pub thumbnail_path: String,
     pub video_path: String,
@@ -28,10 +35,26 @@ pub struct AppState {
     pub insight_generator: InsightGenerator,
 }
 
+impl AppState {
+    pub fn primary_library(&self) -> &Library {
+        self.libraries
+            .first()
+            .expect("AppState constructed without any libraries")
+    }
+
+    pub fn library_by_id(&self, id: i32) -> Option<&Library> {
+        self.libraries.iter().find(|l| l.id == id)
+    }
+
+    pub fn library_by_name(&self, name: &str) -> Option<&Library> {
+        self.libraries.iter().find(|l| l.name == name)
+    }
+}
+
 impl AppState {
     pub fn new(
         stream_manager: Arc<Addr<StreamActor>>,
-        base_path: String,
+        libraries_vec: Vec<Library>,
         thumbnail_path: String,
         video_path: String,
         gif_path: String,
@@ -42,6 +65,11 @@ impl AppState {
         insight_generator: InsightGenerator,
         preview_dao: Arc<Mutex<Box<dyn PreviewDao>>>,
     ) -> Self {
+        assert!(
+            !libraries_vec.is_empty(),
+            "AppState::new requires at least one library"
+        );
+        let base_path = libraries_vec[0].root_path.clone();
         let playlist_generator = PlaylistGenerator::new();
         let video_playlist_manager =
             VideoPlaylistManager::new(video_path.clone(), playlist_generator.start());
@@ -53,6 +81,7 @@ impl AppState {
             stream_manager,
             playlist_manager: Arc::new(video_playlist_manager.start()),
             preview_clip_generator: Arc::new(preview_clip_generator.start()),
+            libraries: libraries_vec,
             base_path,
             thumbnail_path,
             video_path,
@@ -122,8 +151,16 @@ impl Default for AppState {
         let knowledge_dao: Arc<Mutex<Box<dyn KnowledgeDao>>> =
             Arc::new(Mutex::new(Box::new(SqliteKnowledgeDao::new())));
 
-        // Load base path
+        // Load base path and ensure the primary library row reflects it.
         let base_path = env::var("BASE_PATH").expect("BASE_PATH was not set in the env");
+        let mut seed_conn = connect();
+        libraries::seed_or_patch_from_env(&mut seed_conn, &base_path);
+        let libraries_vec = libraries::load_all(&mut seed_conn);
+        assert!(
+            !libraries_vec.is_empty(),
+            "libraries table is empty after seed_or_patch_from_env"
+        );
+        drop(seed_conn);
 
         // Initialize InsightGenerator with all data sources
         let insight_generator = InsightGenerator::new(
@@ -148,7 +185,7 @@ impl Default for AppState {
 
         Self::new(
             Arc::new(StreamActor {}.start()),
-            base_path,
+            libraries_vec,
             env::var("THUMBNAILS").expect("THUMBNAILS was not set in the env"),
             env::var("VIDEO_PATH").expect("VIDEO_PATH was not set in the env"),
             env::var("GIFS_DIRECTORY").expect("GIFS_DIRECTORY was not set in the env"),
@@ -227,9 +264,14 @@ impl AppState {
             Arc::new(Mutex::new(Box::new(SqlitePreviewDao::new())));
 
         // Create the AppState with the temporary paths
+        let test_libraries = vec![Library {
+            id: crate::libraries::PRIMARY_LIBRARY_ID,
+            name: "main".to_string(),
+            root_path: base_path_str.clone(),
+        }];
         AppState::new(
             Arc::new(StreamActor {}.start()),
-            base_path_str,
+            test_libraries,
             thumbnail_path.to_string_lossy().to_string(),
             video_path.to_string_lossy().to_string(),
             gif_path.to_string_lossy().to_string(),