Integrate canonical architecture: two-process backend + LiveKit agent

Promote all 12 staged canonical files from docs/generated/files/ to their
live paths, creating the full PodMan architecture:

Backend:
- server.ts: HTTP service (token mint, sync-PR, outcome recording, /health, WS relay)
- agent.ts: worker joining LiveKit room, grabbing screenshare frames at ~1fps
- agent/podman.ts: orchestrator loop (vision -> collision detection -> intervention)
- env.ts: flat env var accessors replacing nested stub
- vision/gemini.ts: JPEG -> Gemini vision -> EngineerContext (real implementation)
- collision/detector.ts: fused vision+GitHub collision detection (the moat)
- github/client.ts: Octokit wrapper with caching + sync PR creation
- memory/store.ts: extended with recordObservation/recordCollision/recordIntervention/recordOutcome helpers
- memory/vectors.ts: stub for Voyage+Atlas vector recall (Loop A)
- memory/policy.ts: stub for intervention policy gate (Loop B)
- voice/live.ts: stub for Gemini Live TTS voice output

Shared:
- messages.ts: LiveKit data-channel wire protocol (DataMessage, InterventionOutcome, TeamModel, LocalGitReport)
- index.ts: re-exports messages module

Frontend:
- livekit/useScreenPublish.ts: hook for joining pod and publishing screenshare
- livekit/useInterventions.ts: hook for receiving collision cards and responding
- lib/api.ts: fetchToken + postOutcome HTTP helpers

Database:
- database/init.ts: MongoDB Atlas collections + indexes + vector search index

Infra:
- infra/.do/app.yaml: DO App Platform spec (static_site + service + worker)

Retire stubs superseded by canonical decomposition:
- backend/src/index.ts (replaced by server.ts)
- backend/src/intervention/engine.ts (logic now in agent/podman.ts)
- backend/src/livekit/token.ts (token minting now in server.ts)

Install missing dependencies: @livekit/rtc-node, sharp, mongodb, ws, @types/ws

Type error fixes:
- vision/gemini.ts: use MediaResolution.MEDIA_RESOLUTION_LOW enum value (not string literal)
- agent/podman.ts: wrap SuggestedActionKind into { kind: action } SuggestedAction object

All packages pass pnpm -r typecheck and pnpm -r build.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/env.ts

@@ -1,39 +1,35 @@
 import 'dotenv/config';
 
-/** Reads an env var, throwing if it is required but missing. */
-function read(name: string, required = false): string {
-  const value = process.env[name] ?? '';
-  if (required && !value) {
-    throw new Error(`Missing required env var: ${name}`);
-  }
-  return value;
+function req(name: string): string {
+  const v = process.env[name];
+  if (!v) throw new Error(`Missing required env var: ${name}`);
+  return v;
+}
+function opt(name: string, fallback = ''): string {
+  return process.env[name] ?? fallback;
 }
 
 export const env = {
-  port: Number(process.env.PORT ?? 8787),
-
-  livekit: {
-    url: read('LIVEKIT_URL'),
-    apiKey: read('LIVEKIT_API_KEY'),
-    apiSecret: read('LIVEKIT_API_SECRET'),
-  },
-
-  gemini: {
-    apiKey: read('GEMINI_API_KEY'),
-    visionModel: process.env.GEMINI_VISION_MODEL ?? 'gemini-3.5-flash',
-    liveModel: process.env.GEMINI_LIVE_MODEL ?? '',
-  },
-
-  github: {
-    token: read('GITHUB_TOKEN'),
-    repo: read('GITHUB_REPO'),
-  },
-
-  mongo: {
-    uri: read('MONGODB_URI'),
-  },
-
-  voyage: {
-    apiKey: read('VOYAGE_API_KEY'),
-  },
+  // LiveKit
+  LIVEKIT_URL: req('LIVEKIT_URL'),
+  LIVEKIT_API_KEY: req('LIVEKIT_API_KEY'),
+  LIVEKIT_API_SECRET: req('LIVEKIT_API_SECRET'),
+  // Gemini
+  GEMINI_API_KEY: req('GEMINI_API_KEY'),
+  GEMINI_VISION_MODEL: opt('GEMINI_VISION_MODEL', 'gemini-3.5-flash'),
+  GEMINI_LIVE_MODEL: opt('GEMINI_LIVE_MODEL', 'gemini-3.1-flash-live-preview'),
+  // GitHub
+  GITHUB_TOKEN: req('GITHUB_TOKEN'),
+  GITHUB_REPO: req('GITHUB_REPO'), // owner/name
+  // Mongo + Voyage
+  MONGODB_URI: req('MONGODB_URI'),
+  VOYAGE_API_KEY: opt('VOYAGE_API_KEY'),
+  // Server
+  PORT: Number(opt('PORT', '8787')),
 } as const;
+
+export function repoParts(): { owner: string; repo: string } {
+  const [owner, repo] = env.GITHUB_REPO.split('/');
+  if (!owner || !repo) throw new Error('GITHUB_REPO must be "owner/name"');
+  return { owner, repo };
+}