CLI improvements: status/json/wait, config flags, agent installer, CI

[say-michael]

Implements the seven improvement issues opened for this project. Built and smoke-tested against the live SidecarCore framework on macOS 26 (read-only commands verified against a real connected iPad; connect/disconnect not exercised to avoid dropping the live Sidecar session).

What's in here

• Match by identifier(), not name — SidecarDevice.identifier() returns an NSUUID; declaring it as String? crashed with -[__NSConcreteUUID length]. Now read as an object and rendered as a UUID string, used as the identity key for list dedup and status. Closes Match devices by identifier(), not display name #1.
• --wait <seconds> — polls devices() until the target appears before acting, fixing the login auto-connect race. Closes Add --wait flag to poll for device discovery before giving up #2.
• status [name] — exit 0 if connected, 3 if not; human + --json. Closes Add status command with meaningful exit codes #3.
• --json for list (name, identifier, connected). Closes Add --json output for list (and status) #4.
• make install-agent / uninstall-agent + correct plist template in dist/ (old repo file had a sidercar filename typo and was never installed). Bakes the real install path in, loads via launchctl bootstrap, runs connect iPad --wait 60 --quiet at login. Closes Add make install-agent / uninstall-agent with a correct LaunchAgent plist #5.
• version/--version, --quiet, and macOS CI that builds + smoke-tests. Closes Polish: --version, --quiet, suppress NSForwarding stderr noise, CI build check #6.
• --no-sidebar / --no-touchbar via connectToDevice:withConfig:. The live API exposes sidebar/Touch Bar config, not a mirror/extend boolean (that's a CGDisplay concern) — scope adjusted accordingly and documented. Closes Expose mirror vs extend / display arrangement options #7.

Testing

list        → ● Michael's iPad
list --json → [{ "connected": true, "identifier": "83D8...", "name": "Michael's iPad" }]
status      → ● Michael's iPad — connected   (exit 0)
status Foo  → No matching Sidecar device     (exit 3)

Plist validated with plutil -lint; make install-agent dry-run (make -n) confirmed correct path substitution. README updated.

🤖 Generated with Claude Code