feat(storage): add delete_href method to remove files and clean up empty directories

chore(docker): remove MongoDB service and related configurations from local setup

feat(migrations): create ChapterMeta table and add search_name, size_bytes, mtime_epoch, lastScannedAt, review_status, and review_payload columns to SourceAsset

chore(dependencies): remove motor and pymongo from project dependencies

migrations/2026_05_import_search_and_sessions.sql

@@ -0,0 +1,39 @@
+DO $$
+BEGIN
+    CREATE EXTENSION IF NOT EXISTS pg_trgm;
+EXCEPTION
+    WHEN insufficient_privilege THEN NULL;
+END;
+$$;
+
+ALTER TABLE "SourceAsset"
+    ADD COLUMN IF NOT EXISTS search_name TEXT,
+    ADD COLUMN IF NOT EXISTS size_bytes BIGINT,
+    ADD COLUMN IF NOT EXISTS mtime_epoch BIGINT,
+    ADD COLUMN IF NOT EXISTS "lastScannedAt" TIMESTAMPTZ,
+    ADD COLUMN IF NOT EXISTS review_status TEXT NOT NULL DEFAULT 'discovered',
+    ADD COLUMN IF NOT EXISTS review_payload JSONB;
+
+UPDATE "SourceAsset"
+SET search_name = lower(regexp_replace(path, '[^a-zA-Z0-9\s]', ' ', 'g'))
+WHERE search_name IS NULL;
+
+CREATE INDEX IF NOT EXISTS "SourceAsset_search_name_idx" ON "SourceAsset"(search_name);
+CREATE INDEX IF NOT EXISTS "SourceAsset_search_name_trgm_idx" ON "SourceAsset" USING GIN (search_name gin_trgm_ops);
+CREATE INDEX IF NOT EXISTS "SourceAsset_status_updatedAt_idx" ON "SourceAsset"(status, "updatedAt" DESC);
+
+CREATE TABLE IF NOT EXISTS "ImportSession" (
+    id TEXT PRIMARY KEY,
+    "sourceAssetId" TEXT NOT NULL REFERENCES "SourceAsset"(id) ON DELETE CASCADE,
+    "novelId" TEXT,
+    status TEXT NOT NULL DEFAULT 'pending',
+    phase TEXT NOT NULL DEFAULT 'prepare',
+    "progressPct" DOUBLE PRECISION NOT NULL DEFAULT 0,
+    log TEXT,
+    "resultJson" JSONB,
+    "createdBy" TEXT,
+    "createdAt" TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    "updatedAt" TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS "ImportSession_asset_status_idx" ON "ImportSession"("sourceAssetId", status, "updatedAt" DESC);