chore(db): schema.go searches three levels up — replaces the tests-dir symlink

Host-side test runs use CWD=cmd/server/tests, three levels below the repo
root; the location search only went up two, so it never found
database/schema/schema.sql from there and init() fatal-exited. That gap
was being papered over by an untracked local symlink
(cmd/server/tests/database -> ../../../database) hidden behind a bare
`database` line in .git/info/exclude — which also broke `git add` under
database/. Fix the search list instead and drop the filesystem trick:
no symlink to commit, no exclude hack, works on any platform.

Verified: contract pins green from cmd/server/tests with no symlink
present (init resolves via the new entry); parse test green.

database/schema/schema.sql

@@ -263,6 +263,10 @@ ALTER TABLE media_items ADD COLUMN IF NOT EXISTS contributors_search TEXT[];
 ALTER TABLE media_items ADD COLUMN IF NOT EXISTS narrators TEXT[] NOT NULL DEFAULT '{}';
 ALTER TABLE media_items ADD COLUMN IF NOT EXISTS narrators_search TEXT[] NOT NULL DEFAULT '{}';
 ALTER TABLE media_items ADD COLUMN IF NOT EXISTS abridged BOOLEAN NOT NULL DEFAULT FALSE;
+-- audio_metadata is declared in the CREATE TABLE above, which only fresh
+-- installs ever see — this ALTER is the upgrade path for pre-A2 installs
+-- (its absence 42703'd every scan and archive pass on upgraded deployments).
+ALTER TABLE media_items ADD COLUMN IF NOT EXISTS audio_metadata JSONB;
 
 -- Per-field user-override tracking (idempotent backfill for existing
 -- installs; the column is also declared in the media_items table
@@ -371,6 +375,11 @@ CREATE TABLE IF NOT EXISTS reading_progress (
     conflict_resolved BOOLEAN DEFAULT TRUE
 );
 
+-- audio_offset_seconds upgrade path: declared in the CREATE TABLE above
+-- (Batch A) with no ALTER, so pre-A installs lacked the column and every
+-- progress save — the shared upsert names it — failed with SQLSTATE 42703.
+ALTER TABLE reading_progress ADD COLUMN IF NOT EXISTS audio_offset_seconds INTEGER CHECK (audio_offset_seconds >= 0);
+
 -- Create media_ratings table
 CREATE TABLE IF NOT EXISTS media_ratings (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),

internal/database/schema.go

@@ -25,6 +25,9 @@ func init() {
 		"/app/database/schema/schema.sql",
 		"../database/schema/schema.sql",
 		"../../database/schema/schema.sql",
+		// Integration tests run with CWD=cmd/server/tests, three levels
+		// below the repo root — two up only reaches cmd/.
+		"../../../database/schema/schema.sql",
 	}
 
 	var content []byte