rescue(ms-gate-001): preserve uncommitted gatekeeper WIP found in canonical clone (Q19 O1, Jason 2026-08-25)

Gatekeeper module (Gitea PR-webhook -> pending merges), AddPendingMerges
migration, vitest-runner, webhook edits, compose/CI/env/docs touches.
Applied to the tree in a single event 2026-08-23 18:45, author unknown.
Base main@32896770 (2026-03-09). Rescued verbatim for remediation per
board row; no functional review implied.

apps/api/prisma/migrations/20260310120000_AddPendingMerges/migration.sql

@@ -0,0 +1,14 @@
+CREATE TABLE "pending_merges" (
+  "id" UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  "repo" TEXT NOT NULL,
+  "pr_number" INTEGER NOT NULL,
+  "head_sha" TEXT NOT NULL,
+  "state" TEXT NOT NULL DEFAULT 'pending',
+  "review_result" JSONB,
+  "ci_status" TEXT,
+  "requester" TEXT,
+  "gitea_merge_url" TEXT,
+  "created_at" TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  "updated_at" TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  CONSTRAINT "pending_merges_repo_pr_sha_key" UNIQUE ("repo", "pr_number", "head_sha")
+);