[Tooling] Install, detect, and diagnose all supported agents

[teseo]

Kind

implement

Goal

Make installation explicit, idempotent, and diagnosable across all supported CLI agents and desktop modes.

Non-goals

• Silently modifying unrelated agent configuration.
• Installing adapters for agents not in the supported matrix.
• Hiding unsupported desktop behavior.

Invariants

• Existing config is preserved and merges are reversible.
• Detection reports binary, version, surface, and adapter status.
• Re-running install is idempotent.
• Uninstall removes only human.md-owned changes.

Behavioral contract / States

The installer supports auto, explicit agent selection, dry-run, doctor, and uninstall. It reports supported, conditional, advisory, and unsupported states with actionable remediation.

Scope surface

install.sh, uninstall.sh, adapter registration, diagnostics output, and installer tests.

Acceptance

• Test clean install, repeat install, dry-run, doctor, and uninstall in an isolated HOME.
• Test detection with each installed CLI and with missing binaries.
• Run: bash tests/test_install.sh and add assertions for idempotence and non-destructive config merges.
• Doctor output must identify the exact adapter and hook path in use.

Split triggers

• An agent requires an installer language/runtime not shared by the core.
• Config ownership cannot be safely detected or reversed.

Dependencies / Parent

Blocked by: #4, #5, #6, #7, #8, #9, #10
Parent Epic: #15