feat: add proxyctl daemon manager, fix standalone LS cleanup

- Add proxyctl CLI script for systemd service management
- Add systemd user service file for background operation
- Fix standalone LS kill: properly track real LS PID via pgrep
  and use sudo kill for cross-user cleanup on shutdown
- Remove deprecated scripts (dns-redirect, iptables-redirect,
  mitm-wrapper, standalone-ls, parse-snapshot)
- Disable tool stripping in MITM for tool call investigation
- Update GEMINI.md with CLI tools documentation

GEMINI.md

@@ -5,24 +5,46 @@ OpenAI-compatible proxy that intercepts and relays requests to Google's Antigrav
 ## Quick Start
 
 ```bash
-# Build
-cargo build --release
-
 # First-time setup (creates user + iptables for MITM)
 sudo ./scripts/mitm-redirect.sh install
 
-# Run (spawns standalone LS automatically)
+# Start as daemon (builds if needed)
+proxyctl start
+
+# Or run directly
 RUST_LOG=info ./target/release/antigravity-proxy
-
-# Custom port
-RUST_LOG=info ./target/release/antigravity-proxy --port 9000
-
-# Attach to existing LS instead of spawning standalone
-RUST_LOG=info ./target/release/antigravity-proxy --no-standalone
 ```
 
 Default port: **8741**
 
+## CLI Tools
+
+### `proxyctl` — Daemon Manager
+
+Symlinked to `~/.local/bin/proxyctl` for global access. Manages the proxy as a systemd user service.
+
+| Command               | Description                             |
+| --------------------- | --------------------------------------- |
+| `proxyctl start`      | Start the proxy daemon                  |
+| `proxyctl stop`       | Stop the proxy daemon                   |
+| `proxyctl restart`    | Rebuild + restart                       |
+| `proxyctl rebuild`    | Build release binary only               |
+| `proxyctl status`     | Service status + quota + usage          |
+| `proxyctl logs [N]`   | Tail last N lines (default 30) + follow |
+| `proxyctl logs-all`   | Full log dump (no follow)               |
+| `proxyctl test [msg]` | Quick test request (gemini-3-flash)     |
+| `proxyctl health`     | Health check                            |
+
+### `mitm-redirect.sh` — MITM Setup
+
+One-time setup script for UID-scoped iptables traffic redirection.
+
+```bash
+sudo ./scripts/mitm-redirect.sh install    # create user + iptables rule
+sudo ./scripts/mitm-redirect.sh uninstall  # remove user + iptables rule
+sudo ./scripts/mitm-redirect.sh status     # check current state
+```
+
 ## Endpoints
 
 | Method   | Path                   | Description                                                 |