fix(core): SQLite timeout=30, INSERT OR IGNORE migrations, parameterize tier unlockables

- get_connection(): add timeout=30 to both sqlite3 and pysqlcipher3 paths so
  concurrent writers retry instead of immediately raising OperationalError
- run_migrations(): INSERT OR IGNORE so two Store() calls racing on first boot
  don't hit a UNIQUE constraint on the migrations table
- can_use() / tier_label(): accept _byok_unlockable and _local_vision_unlockable
  overrides so products pass their own frozensets rather than sharing module-level
  constants (required for circuitforge-core to serve multiple products cleanly)

circuitforge_core/db/base.py

@@ -22,7 +22,9 @@ def get_connection(db_path: Path, key: str = "") -> sqlite3.Connection:
     cloud_mode = os.environ.get("CLOUD_MODE", "").lower() in ("1", "true", "yes")
     if cloud_mode and key:
         from pysqlcipher3 import dbapi2 as _sqlcipher  # type: ignore
-        conn = _sqlcipher.connect(str(db_path))
+        conn = _sqlcipher.connect(str(db_path), timeout=30)
         conn.execute(f"PRAGMA key='{key}'")
         return conn
-    return sqlite3.connect(str(db_path))
+    # timeout=30: retry for up to 30s when another writer holds the lock (WAL mode
+    # allows concurrent readers but only one writer at a time).
+    return sqlite3.connect(str(db_path), timeout=30)

circuitforge_core/db/migrations.py

@@ -23,5 +23,7 @@ def run_migrations(conn: sqlite3.Connection, migrations_dir: Path) -> None:
         if sql_file.name in applied:
             continue
         conn.executescript(sql_file.read_text())
-        conn.execute("INSERT INTO _migrations (name) VALUES (?)", (sql_file.name,))
+        # OR IGNORE: safe if two Store() calls race on the same DB — second writer
+        # just skips the insert rather than raising UNIQUE constraint failed.
+        conn.execute("INSERT OR IGNORE INTO _migrations (name) VALUES (?)", (sql_file.name,))
         conn.commit()

circuitforge_core/tiers/tiers.py

@@ -30,6 +30,8 @@ def can_use(
     has_byok: bool = False,
     has_local_vision: bool = False,
     _features: dict[str, str] | None = None,
+    _byok_unlockable: frozenset[str] | None = None,
+    _local_vision_unlockable: frozenset[str] | None = None,
 ) -> bool:
     """
     Return True if the given tier (and optional unlocks) can access feature.
@@ -41,15 +43,22 @@ def can_use(
         has_local_vision:       True if user has a local vision model configured.
         _features:              Feature→min_tier map. Products pass their own dict here.
                                 If None, all features are free.
+        _byok_unlockable:       Product-specific BYOK-unlockable features.
+                                If None, uses module-level BYOK_UNLOCKABLE.
+        _local_vision_unlockable: Product-specific local vision unlockable features.
+                                  If None, uses module-level LOCAL_VISION_UNLOCKABLE.
     """
     features = _features or {}
+    byok_unlockable = _byok_unlockable if _byok_unlockable is not None else BYOK_UNLOCKABLE
+    local_vision_unlockable = _local_vision_unlockable if _local_vision_unlockable is not None else LOCAL_VISION_UNLOCKABLE
+
     if feature not in features:
         return True
 
-    if has_byok and feature in BYOK_UNLOCKABLE:
+    if has_byok and feature in byok_unlockable:
         return True
 
-    if has_local_vision and feature in LOCAL_VISION_UNLOCKABLE:
+    if has_local_vision and feature in local_vision_unlockable:
         return True
 
     min_tier = features[feature]
@@ -64,13 +73,18 @@ def tier_label(
     has_byok: bool = False,
     has_local_vision: bool = False,
     _features: dict[str, str] | None = None,
+    _byok_unlockable: frozenset[str] | None = None,
+    _local_vision_unlockable: frozenset[str] | None = None,
 ) -> str:
     """Return a human-readable label for the minimum tier needed for feature."""
     features = _features or {}
+    byok_unlockable = _byok_unlockable if _byok_unlockable is not None else BYOK_UNLOCKABLE
+    local_vision_unlockable = _local_vision_unlockable if _local_vision_unlockable is not None else LOCAL_VISION_UNLOCKABLE
+
     if feature not in features:
         return "free"
-    if has_byok and feature in BYOK_UNLOCKABLE:
+    if has_byok and feature in byok_unlockable:
         return "free (BYOK)"
-    if has_local_vision and feature in LOCAL_VISION_UNLOCKABLE:
+    if has_local_vision and feature in local_vision_unlockable:
         return "free (local vision)"
     return features[feature]