bambox doctor: diagnostic command for support triage

[pzfreo]

Idea

Add a `bambox doctor` subcommand that prints a single self-contained diagnostic blob users can paste into a bug report. It should answer: what's installed, what's configured, what's reachable, and what recently went wrong — without making the user learn `RUST_LOG` or hunt through `~/.config`.

Suggested output

• `bambox` version + Python version + platform (OS, arch)
• Bridge mode in use (native binary path / Docker image tag) and its version (via the daemon version handshake from Bridge version check: expose version via HTTP, Python validates compatibility #155 / feat: bridge version check on daemon connect #185)
• Whether Docker is installed and the daemon is reachable
• Whether `~/.config/estampo/credentials.toml` exists, is readable, and how many printers it lists (names only, no secrets)
• Last N lines of the bridge log (if a daemon is running)
• Result of a `/ping` against a running daemon, if any
• Network reachability sanity check to the Bambu Cloud endpoint

Scope-out

• No automatic upload anywhere — output is local stdout, user controls what to share
• No secret material in the output (mask access tokens, device serials optional)
• No fix-it actions — diagnosis only, this is not `bambox repair`

Priority

Post v0.5. Soft-launch readiness is being handled via README updates, known-limitations docs, the e2e walkthrough, and the release workflow fix. `doctor` is the next layer of support polish — valuable once real users start filing bugs, not blocking on day one.

Why it pays off

Once strangers start filing bugs, the first round-trip on every issue is "what version, what OS, native or Docker, can you paste the bridge log" — `bambox doctor` collapses that into a single command and dramatically shortens the support loop.