feat(license): add gyandoot-license crate + CLI subcommand

- New crate: gyandoot-license with:
  - Machine fingerprinting (CPU, MAC, Disk, hostname)
  - Ed25519 JWT signing and verification
  - Agent counting with RAII guards
  - AES-256-GCM encrypted license cache
  - Anti-tamper binary integrity checks
  - Debugger detection
- Added to workspace Cargo.toml
- Added 'gyandoot license' CLI subcommand (activate, status, deactivate, fingerprint)

Cargo.toml

@@ -21,6 +21,7 @@ members = [
     "crates/gyandoot-gateway",
     "crates/gyandoot-browser",
     "crates/gyandoot-tui",
+    "crates/gyandoot-license",
 ]
 
 [workspace.package]
@@ -73,6 +74,7 @@ gyandoot-profile = { path = "crates/gyandoot-profile" }
 gyandoot-gateway = { path = "crates/gyandoot-gateway" }
 gyandoot-browser = { path = "crates/gyandoot-browser" }
 gyandoot-tui = { path = "crates/gyandoot-tui" }
+gyandoot-license = { path = "crates/gyandoot-license" }
 tokio.workspace = true
 serde.workspace = true
 serde_json.workspace = true