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/indexer/src/job.rs

@@ -3,7 +3,7 @@ use sqlx::{PgPool, Row};
 use tracing::{error, info};
 use uuid::Uuid;
 
-use crate::{analyzer, converter, meili, scanner, AppState};
+use crate::{analyzer, converter, scanner, AppState};
 
 pub async fn cleanup_stale_jobs(pool: &PgPool) -> Result<()> {
     let result = sqlx::query(
@@ -337,9 +337,6 @@ pub async fn process_job(
         }
     }
 
-    // Sync search index after discovery (books are visible immediately)
-    meili::sync_meili(&state.pool, &state.meili_url, &state.meili_master_key).await?;
-
     // For full rebuild: clean up orphaned thumbnail files (old UUIDs)
     if is_full_rebuild {
         analyzer::cleanup_orphaned_thumbnails(state).await?;