feat: ship production deploy, Playwright e2e, and agent implementer

Add Docker atomic deploy tooling, CI, Playwright smoke/visual suite,
shared industrial theme, physics invariants, quality-mode wiring,
and a worktree-isolated agent implementer MVP with hard safety limits.

Co-authored-by: Cursor <cursoragent@cursor.com>

agent/tasks/demo-docs.json

@@ -0,0 +1,14 @@
+{
+  "id": "demo-docs",
+  "title": "Add agent cycle demo documentation",
+  "slug": "demo-docs",
+  "policyCategory": "docs",
+  "description": "Safe docs-only demo patch for the Implementer MVP. No LLM required. Creates docs/AGENT_CYCLE_DEMO.md inside an isolated git worktree.",
+  "allowPaths": ["docs/AGENT_CYCLE_DEMO.md"],
+  "requiresLlm": false,
+  "patch": {
+    "type": "create-file",
+    "path": "docs/AGENT_CYCLE_DEMO.md",
+    "contentTemplate": "builtin-demo-docs"
+  }
+}