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>

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Stian
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.