Add IP Vault: Cryptographic proof-of-origin system

Implements a complete vertical slice of the IP Vault feature for BlackRoad OS,
providing cryptographic timestamping and evidence generation for ideas and
intellectual property.

## Components Added

### Agent Layer
- **VaultAgent** (`agents/categories/security/vault_agent.py`):
  - Deterministic text canonicalization
  - Multi-hash generation (SHA-256, SHA-512, Keccak-256)
  - LEO (Ledger Evidence Object) construction
  - Verification text generation
  - Blockchain anchoring preparation

### Backend API
- **Models** (`backend/app/models/leo.py`):
  - LEO: Stores cryptographic hashes and metadata
  - AnchorEvent: Audit trail for blockchain anchoring

- **Schemas** (`backend/app/schemas/leo.py`):
  - LEOCreate, LEOResponse, LEODetail, LEOList
  - AnchorRequest, AnchorEventResponse

- **Router** (`backend/app/routers/ip_vault.py`):
  - POST /api/vault/leos - Create new LEO
  - GET /api/vault/leos - List LEOs (paginated)
  - GET /api/vault/leos/{id} - Get LEO details
  - POST /api/vault/leos/{id}/anchor - Initiate anchoring (stub)
  - GET /api/vault/leos/{id}/events - Get anchor events

### Frontend
- **API Client** (`backend/static/js/api-client.js`):
  - createLEO(), getLEOs(), getLEO()
  - anchorLEO(), getLEOEvents()

- **App** (`backend/static/js/apps.js`):
  - loadIPVault() - Load and display LEOs
  - vaultIdea() - Create new LEO from form
  - viewLEO() - Show detailed LEO modal with verification

- **UI** (`backend/static/index.html`):
  - Desktop icon (🔐 IP Vault)
  - Window with form and list view
  - Start menu integration

## Features

- **Deterministic canonicalization**: Ensures reproducible hashing
- **Multi-hash support**: SHA-256, SHA-512, Keccak-256 (Ethereum-compatible)
- **Verification instructions**: Auto-generated proof-of-authenticity text
- **Blockchain-ready**: Prepared for Bitcoin, Litecoin, Ethereum anchoring
- **Clean separation**: Agent logic, API, database, frontend all decoupled

## Testing

- Python syntax validated for all new files
- JavaScript syntax validated
- VaultAgent tested end-to-end with sample idea
- All hashes computed successfully

## Next Steps

- Implement actual blockchain anchoring
- Add RoadChain integration
- Export LEOs as legal-grade PDFs
- Add user authentication to LEO creation

backend/app/models/leo.py

@@ -0,0 +1,77 @@
+"""LEO (Ledger Evidence Object) model"""
+from sqlalchemy import Column, Integer, String, DateTime, Text
+from sqlalchemy.sql import func
+from app.database import Base
+
+
+class LEO(Base):
+    """
+    Ledger Evidence Object (LEO) model
+
+    Cryptographic proof-of-origin for ideas and intellectual property.
+    Stores hashes and metadata suitable for blockchain anchoring.
+    """
+
+    __tablename__ = "leos"
+
+    id = Column(String(36), primary_key=True, index=True)  # UUID
+    author = Column(String(255), nullable=False, default="Alexa")
+    title = Column(String(500), nullable=True)
+
+    # Cryptographic hashes
+    sha256 = Column(String(64), nullable=False, index=True)
+    sha512 = Column(String(128), nullable=False)
+    keccak256 = Column(String(64), nullable=False)
+
+    # Metadata
+    canonical_size = Column(Integer, nullable=False)
+
+    # Blockchain anchoring
+    anchor_status = Column(
+        String(20),
+        nullable=False,
+        default="pending"
+    )  # pending, anchored, failed
+    anchor_txid = Column(String(128), nullable=True)
+    anchor_chain = Column(String(50), nullable=True)
+    anchor_block_height = Column(Integer, nullable=True)
+    anchored_at = Column(DateTime(timezone=True), nullable=True)
+
+    # Timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+
+    def __repr__(self):
+        return f"<LEO {self.id} by {self.author}>"
+
+
+class AnchorEvent(Base):
+    """
+    Blockchain anchor event audit trail
+
+    Tracks all anchoring attempts and status changes for LEOs.
+    """
+
+    __tablename__ = "anchor_events"
+
+    id = Column(Integer, primary_key=True, index=True)
+    leo_id = Column(String(36), nullable=False, index=True)
+
+    # Event details
+    event_type = Column(String(50), nullable=False)  # anchor_initiated, anchor_confirmed, anchor_failed
+    chain = Column(String(50), nullable=True)
+    txid = Column(String(128), nullable=True)
+    block_height = Column(Integer, nullable=True)
+
+    # Status
+    status = Column(String(20), nullable=False)  # pending, confirmed, failed
+    error_message = Column(Text, nullable=True)
+
+    # Metadata
+    metadata = Column(Text, nullable=True)  # JSON serialized
+
+    # Timestamps
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+    def __repr__(self):
+        return f"<AnchorEvent {self.id} for LEO {self.leo_id}>"