docs: add Show HN draft for clavitor.ai launch (TASK-072)

docs/LAUNCH-CHECKLIST.md

@@ -31,7 +31,7 @@
 - [ ] Schedule launch (weekday, Tuesday–Thursday best)
 
 ### HackerNews
-- [ ] Draft "Show HN: Clavitor – Password manager with two-tier encryption for humans with AI assistants"
+- [x] Draft "Show HN: Clavitor – Password manager with two-tier encryption for humans with AI assistants" → docs/SHOW-HN.md
 - [ ] Time for Monday morning ET (highest engagement)
 
 ---

docs/SHOW-HN.md

@@ -0,0 +1,81 @@
+# Show HN: Clavitor – Password manager with two-tier encryption for humans with AI assistants
+
+**TL;DR:** A password manager that knows your AI assistant needs your GitHub key, but doesn't need your CVV. Field-level encryption with WebAuthn PRF for L2 secrets. One Go binary, MIT licensed.
+
+---
+
+## The Problem
+
+Your Claude/Codex/Cursor agent needs credentials to deploy code, rotate keys, complete 2FA. But every existing password manager is all-or-nothing:
+
+- Give the AI your vault password → it sees everything (including your credit card)
+- Don't give it access → it can't do its job
+
+We needed per-field visibility. So we built it.
+
+---
+
+## Two-Tier Encryption
+
+**L1 (Credential Encryption):** Server-side key. AI-readable. API keys, SSH keys, TOTP secrets.
+
+**L2 (Identity Encryption):** WebAuthn PRF, client-side only. Card numbers, CVV, passport, private keys. The server literally cannot decrypt these — the key is derived from your Touch ID / Face ID / YubiKey in the browser and never leaves.
+
+Same entry. Two encryption tiers. The AI sees the GitHub token. It sees that you *have* an Amex card. It cannot see the card number.
+
+---
+
+## Technical Details
+
+- **One binary:** `clavitor` → SQLite file on port 1984. No Docker, no Postgres, no Redis.
+- **MCP-native:** `/mcp` endpoint with `get_credential()`, `get_totp()`, `check_expiring()`. Works with Claude Code, Cursor, Codex.
+- **LLM import:** Native parsers for Chrome/Firefox/Bitwarden/Proton (12k+ entries instant). LLM fallback for any other format.
+- **Collision resolution:** Import from multiple sources, newest `timePasswordChanged` wins per entry.
+- **FIPS 140-3:** Go crypto with CNG/OpenSSL backends where available.
+
+---
+
+## Why This Matters
+
+LastPass lost encrypted vaults in 2022. Three years later, attackers are still cracking them — weak passwords first. FBI traced $150M+ in crypto theft to that single breach.
+
+Clavitor's L2 fields use WebAuthn PRF. The server never has the key. Even shell access to the box doesn't get your credit card numbers. Math, not policy.
+
+---
+
+## Quick Start
+
+```bash
+# Self-host in 30 seconds
+curl -fsSL clavitor.ai/install.sh | sh
+./clavitor
+# Running on http://localhost:1984
+
+# Claude Code MCP config
+~/.claude/mcp.json:
+{
+  "mcpServers": {
+    "clavitor": {
+      "command": "clavitor",
+      "args": ["mcp"]
+    }
+  }
+}
+```
+
+---
+
+## Code & License
+
+- **GitHub:** https://github.com/johanj/clavitor
+- **License:** MIT
+- **Language:** Go 1.24
+- **Platforms:** Linux/amd64, Linux/arm64, Darwin/arm64, Darwin/amd64
+
+The port number is intentional.
+
+---
+
+## Questions? 
+
+AMA in comments. Happy to discuss the WebAuthn PRF implementation, the MCP protocol design, or why we chose SQLite over "web scale" alternatives.