fix(mcp): tool allowlist stored/read as jsonb string, not array

Opening the edit form for an MCP server that has a saved tool allowlist crashed
the whole settings page (`TypeError: Ke.map is not a function` in Mantine) — and,
worse, the allowlist was silently NOT enforced. Both stem from one root cause:
the `tool_allowlist` jsonb column round-trips as a JSON STRING, not an array.

Root cause: `jsonbArray` bound `JSON.stringify(value)` (already a JSON string)
straight to a `::jsonb` cast. node-postgres infers the param type as jsonb and
JSON-stringifies it a SECOND time, so the column stored a jsonb STRING SCALAR
(`"[\"a\"]"`, jsonb_typeof = string) instead of an array. On read the driver
hands back the JS string `'["a"]'`. Then:
  - the edit form's TagsInput called `.map` on a string -> page crash;
  - mcp-clients did `Array.isArray(allow)` -> false for a string -> fell through
    to "no restriction" and exposed ALL of the server's tools.

Fix (both verified on the stand):
- Write: `jsonbArray` casts `::text::jsonb` so the param is bound as text (sent
  verbatim) and parsed into a real jsonb array. New rows now store
  jsonb_typeof=array.
- Read: `normalizeRow` runs every fetched row through `parseToolAllowlist`, which
  returns `string[] | null` for both shapes (already-array passes through; a JSON
  string is parsed; null/invalid -> null). This REPAIRS existing double-encoded
  rows on read, so the UI and the allowlist enforcement work without a data
  migration. Applied in findById / listByWorkspace / listEnabled.
- Client: defensive `Array.isArray(...) ? ... : []` guard in the form so a bad
  shape can never take the settings page down again.

Tests: ai-mcp-server.repo.spec (8 cases for parseToolAllowlist — array, the
JSON-string read, null, empty, non-array json, unparseable, non-string elements,
non-string primitive). mcp-servers-to-view + mcp-namespacing still green.
Verified live: an old double-encoded row now reads as an array; a newly created
server stores jsonb_typeof=array.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-form.tsx

@@ -56,7 +56,13 @@ function buildInitialValues(server?: IAiMcpServer): FormValues {
     transport: server?.transport ?? "http",
     url: server?.url ?? "",
     authHeader: "",
-    toolAllowlist: server?.toolAllowlist ?? [],
+    // Defensive: TagsInput calls `.map`, so a non-array here (e.g. an API that
+    // returns the jsonb column as a JSON string) would crash the whole page. The
+    // server normalizes this now, but guard anyway so a bad shape can never take
+    // the settings UI down.
+    toolAllowlist: Array.isArray(server?.toolAllowlist)
+      ? server.toolAllowlist
+      : [],
     enabled: server?.enabled ?? true,
   };
 }