refactor: replace Meilisearch with PostgreSQL full-text search

Remove Meilisearch dependency entirely. Search is now handled by
PostgreSQL ILIKE with pg_trgm indexes, joining series_metadata for
series-level authors. No external search engine needed.

- Replace search.rs Meilisearch HTTP calls with PostgreSQL queries
- Remove meili.rs from indexer, sync_meili call from job pipeline
- Remove MEILI_URL/MEILI_MASTER_KEY from config, state, env files
- Remove meilisearch service from docker-compose.yml
- Add migration 0027: drop sync_metadata, enable pg_trgm, add indexes
- Remove search resync button/endpoint (no longer needed)
- Update all documentation (CLAUDE.md, README.md, AGENTS.md, PLAN.md)

API contract unchanged — same SearchResponse shape returned.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/settings.rs

@@ -42,7 +42,6 @@ pub fn settings_routes() -> Router<AppState> {
         .route("/settings/cache/clear", post(clear_cache))
         .route("/settings/cache/stats", get(get_cache_stats))
         .route("/settings/thumbnail/stats", get(get_thumbnail_stats))
-        .route("/settings/search/resync", post(force_search_resync))
 }
 
 /// List all settings
@@ -325,27 +324,3 @@ pub async fn get_thumbnail_stats(State(_state): State<AppState>) -> Result<Json<
 
     Ok(Json(stats))
 }
-
-/// Force a full Meilisearch resync by resetting the sync timestamp
-#[utoipa::path(
-    post,
-    path = "/settings/search/resync",
-    tag = "settings",
-    responses(
-        (status = 200, description = "Resync scheduled"),
-        (status = 401, description = "Unauthorized"),
-    ),
-    security(("Bearer" = []))
-)]
-pub async fn force_search_resync(
-    State(state): State<AppState>,
-) -> Result<Json<Value>, ApiError> {
-    sqlx::query("UPDATE sync_metadata SET last_meili_sync = NULL WHERE id = 1")
-        .execute(&state.pool)
-        .await?;
-
-    Ok(Json(serde_json::json!({
-        "success": true,
-        "message": "Search resync scheduled. The indexer will perform a full sync on its next cycle."
-    })))
-}