disktree-cli: the scan, findings and removal guards without a window

[NakliTechie]

Disk cleanup is becoming agent work, and disktree already knows it: its review screen hands the marked list to a coding agent, and "Agent scratch" is one of its categories. This PR adds the other direction: an agent can ask disktree what fills a disk, and remove only through disktree's own guards.

Three commits, each reviewable on its own:

1. core: move git state into disktree-core. git.rs moves from the app to core, unchanged, so a checkout's changes, stashes and unpushed commits can be read without a window. No behaviour change.
2. insights: model weights, stale archives, and .worktrees. Worth a look now lists two things a developer machine forgets. The panel labels both "check for a copy", not "safe to delete".
   • Weights: a directory holding .safetensors, .gguf, .ggml, .ckpt, .pt, .pth, .onnx or .tflite directly. A .bin counts only beside a config.json, the Hugging Face shape. Only the weight files are counted.
   • Stale archive: an archive or disk image untouched for 30 days. Synced folders are skipped, since an old archive there is a backup.
   • .worktrees is treated like worktrees.
3. disktree-cli. Three commands, each printing JSON:

   disktree-cli scan [PATH] [--store DIR]... [--limit N]
   disktree-cli check --root ROOT PATH...
   disktree-cli trash --root ROOT PATH...
   

   • Each finding carries a tier. regenerable is space a tool or build writes again. judge is space that may be the only copy. Worktree findings include each checkout's git state.
   • --store names a directory kept on purpose, such as a model store. Findings inside it are left out. A weight file elsewhere with the same name and size is reported as a copy of the one in the store.
   • --root is required for check and trash, as the scanned root is the consent boundary in the window. trash is the only way it removes anything. There is no permanent mode.

The one new dependency is serde_json, in the CLI crate only.

Checks

• cargo xtask lint: clean on Rust 1.98.1.
• cargo xtask test: 173 passed, 0 failed. That includes 5 new insights tests and 3 CLI tests: a store match, guard refusals, and --root required.
• On an M-series Mac: disktree-cli scan ~/Code took 22 s for 1.63M files, 206 GB.
• check refused home, the scanned root, and a path under /private.
• trash moved a test directory to the macOS Trash.
• Not run: Linux and Windows. The CLI adds no platform code apart from a cfg(unix) block size, with a len() fallback elsewhere.

README gains a "Without a window" section. AGENTS.md's map gains git.rs and the CLI.

Happy to split this into three PRs, or to drop the CLI and keep only the findings, if that fits the project better.

🤖 Generated with Claude Code