Add extension store publishing documentation

- Store description for Chrome Web Store and Firefox Add-ons
- Privacy policy (no data collection, local-only storage)
- Comprehensive publishing guide with checklists

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/store/STORE_DESCRIPTION.md

@@ -0,0 +1,88 @@
+# Plebeian Signer - Store Description
+
+Use this content for Chrome Web Store and Firefox Add-ons listings.
+
+---
+
+## Short Description (132 characters max for Chrome)
+
+Secure Nostr identity manager. Sign events without exposing private keys. Multi-identity support with NIP-07 compatibility.
+
+---
+
+## Full Description
+
+**Plebeian Signer** is a secure browser extension for managing your Nostr identities and signing events without exposing your private keys to web applications.
+
+### Key Features
+
+**Multi-Identity Management**
+- Create and manage multiple Nostr identities from a single extension
+- Easily switch between identities with one click
+- Import existing keys or generate new ones
+
+**Bank-Grade Security**
+- Private keys never leave the extension
+- Vault encrypted with Argon2id + AES-256-GCM (the same algorithms used by password managers)
+- Automatic vault locking for protection
+
+**NIP-07 Compatible**
+- Works with all Nostr web applications that support NIP-07
+- Supports NIP-04 and NIP-44 encryption/decryption
+- Relay configuration per identity
+
+**Permission Control**
+- Fine-grained permission management per application
+- Approve or deny signing requests on a per-site basis
+- Optional "Reckless Mode" for trusted applications
+- Whitelist trusted hosts for automatic approval
+
+**User-Friendly Interface**
+- Clean, intuitive design
+- Profile metadata display with avatar and banner
+- NIP-05 verification support
+- Bookmark your favorite Nostr apps
+
+### How It Works
+
+1. Create a password-protected vault
+2. Add your Nostr identities (import existing or generate new)
+3. Visit any NIP-07 compatible Nostr application
+4. Approve signing requests through the extension popup
+
+### Privacy First
+
+Plebeian Signer is open source and respects your privacy:
+- No telemetry or analytics
+- No external servers (except for profile metadata from Nostr relays)
+- All cryptographic operations happen locally in your browser
+- Your private keys are encrypted and never transmitted
+
+### Supported NIPs
+
+- NIP-07: Browser Extension for Nostr
+- NIP-04: Encrypted Direct Messages
+- NIP-44: Versioned Encryption
+
+### Links
+
+- Source Code: https://git.mleku.dev/mleku/plebeian-signer
+- Report Issues: https://git.mleku.dev/mleku/plebeian-signer/issues
+
+---
+
+## Category Suggestions
+
+**Chrome Web Store:**
+- Primary: Productivity
+- Secondary: Developer Tools
+
+**Firefox Add-ons:**
+- Primary: Privacy & Security
+- Secondary: Other
+
+---
+
+## Tags/Keywords
+
+nostr, nip-07, signing, identity, privacy, encryption, decentralized, keys, wallet, security