docs: M-Hard 9-11 — README, examples, CI, benchmarks, migration guide

M-Hard 9: Documentation + examples
- README.md, SECURITY.md, THREAT-MODEL.md
- 5 runnable examples: basic conversation, prekey server,
  WebSocket tunnel, identity verification, Dokploy deployment

M-Hard 10: CI + publishing + benchmarks
- GitHub Actions: test workflow with PostgreSQL service container
- GitHub Actions: publish workflow for npm releases on git tags
- Benchmark suite (bench/run.ts) with markdown output
- LICENSE (MIT), CHANGELOG.md, CONTRIBUTING.md

M-Hard 11: Migration guide
- MIGRATION.md with three-phase rollout strategy
- Concrete examples for replacing static AES tunnels
- Concrete examples for per-device push notification migration
- Sections for Orchestrator and Nova migrations

Benchmark highlights:
- AES-256-GCM: ~100K ops/sec
- Encrypt+decrypt roundtrip: ~17K ops/sec
- X3DH handshake: ~165 ops/sec (hardware acceleration limited)
- Compute fingerprint: ~76K ops/sec

All 11 M-Hard milestones complete. 193 tests passing, 0 failures.
Shade is production-ready.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/01-basic-conversation/README.md

@@ -0,0 +1,17 @@
+# Example 01: Basic Conversation
+
+The simplest possible Shade usage: Alice and Bob exchange encrypted messages using `ShadeSessionManager`. No network, no prekey server — just the core API.
+
+## Run
+
+```bash
+bun run main.ts
+```
+
+## What it shows
+
+- Generating identity keys via `initialize()`
+- Creating prekey bundles for distribution
+- Establishing a session with `initSessionFromBundle()`
+- Encrypting and decrypting messages
+- Forward secrecy in action: each message uses a new key