[FEATURE] Developer experience suite — `doctor`, `sessions`, `upgrade`, install flags

[Wolfvin]

Summary

Add 4 DX commands to reduce support burden and improve onboarding: codelens doctor (environment audit + auto-fix), codelens sessions (installer session log viewer), codelens upgrade (in-place self-update), install.sh --dry-run/--self-test/--uninstall.

Worker consensus (2 reports)

Worker	Source	Contribution
UBS	update!/CodeLens_UBS_Upgrade_Analysis.md #3	codelens doctor — audit Python version, tree-sitter + 6 grammars, PyYAML, watchdog, git, SQLite, urllib, writable .codelens/. --fix auto-installs missing deps. --verbose, --format=json. Exit codes 0/1/2. Integrate with setup.sh.
UBS	same file #13	codelens sessions — setup.sh appends Markdown session log to ~/.codelens/session.md per install. --entries=N, --raw, --config-dir, --json. Rotate if >1MB (keep last 50).
UBS	same file #25	install.sh --dry-run (print actions without touching disk), --self-test (run smoke test post-install), --uninstall (delete binary, remove RC snippets, remove ~/.codelens/, remove agent hooks, --non-interactive). Track written files in ~/.codelens/installed-files.txt.
CodeGraph	update!/CodeLens_CodeGraph_Upgrade_Analysis.md #12	codelens upgrade [version] — detect install method (pip, homebrew, source, binary), update accordingly. --check, --force, codelens upgrade <version> (pin). Windows: spawn DETACHED helper.

Proposed scope (P2, 3-4 weeks total)

Phase 1 — codelens doctor (P1, 3-5 days, quick win)

• New scripts/commands/doctor.py
• Audit:
  • Python version (3.8+)
  • tree-sitter core
  • 6 grammar packages (html, css, javascript, typescript, rust, python)
  • PyYAML
  • watchdog (optional)
  • git (optional, for ownership)
  • SQLite
  • urllib
  • Writable .codelens/ dirs
  • Latest available CodeLens version (via GitHub Releases API)
• --fix auto-install missing deps via pip install --user
• --verbose shows full diagnostic
• --format=json for CI parsing
• Color output with ✓/✗ symbols
• Exit codes: 0 OK / 1 warning / 2 critical missing
• Integrate with setup.sh to run at end of setup

Phase 2 — codelens sessions (P2, 3-5 days)

• setup.sh appends Markdown session log to ~/.codelens/session.md per install
• Log fields: duration, Python/OS/arch, detected agents with ✓/✗, configured integrations, dependencies installed, warnings, errors
• JSON sidecar at ~/.codelens/session.json for programmatic access
• New scripts/commands/sessions.py
• --entries=N (last N sessions, default 5)
• --raw (full unformatted)
• --config-dir=<path>
• --json
• Rotate if >1MB (keep last 50 sessions)
• Integrate with doctor for diagnosis

Phase 3 — install.sh safety flags (P2, 3-5 days, depends on distribution issue)

• --dry-run — print all install actions without touching disk, "WOULD: ..." for every write op
• --self-test — run smoke test post-install via pytest test-suite/install/, exit non-zero on failure
• --uninstall — delete binary, remove shell RC snippets/aliases, remove ~/.codelens/, remove agent hooks
• --non-interactive for scripted uninstall
• Track all written files in ~/.codelens/installed-files.txt for clean uninstall

Phase 4 — codelens upgrade (P2, 1 week, depends on distribution issue)

• New scripts/commands/upgrade.py
• Detect install method: pip, homebrew, source (via .git), binary
• codelens upgrade — update to latest
• codelens upgrade <version> — pin to specific version
• codelens upgrade --check — compare current vs latest GitHub Release, exit 0/1
• codelens upgrade --force — force reinstall
• Windows wrinkle: spawn DETACHED helper (subprocess.Popen with CREATE_NEW_PROCESS_GROUP) that waits for current process exit then runs installer (rustup/nvm-windows pattern)
• Version check fetches https://api.github.com/repos/Wolfvin/CodeLens/releases/latest, compares tag_name with CODELENS_VERSION

Acceptance criteria

• codelens doctor correctly detects all missing dependencies
• codelens doctor --fix installs missing deps without error
• codelens sessions shows last 5 install sessions
• install.sh --dry-run produces no filesystem changes
• install.sh --uninstall removes all installed files (verified by installed-files.txt)
• codelens upgrade --check correctly compares versions
• codelens upgrade works for pip / homebrew / source install methods

Files

• New: scripts/commands/{doctor,sessions,upgrade}.py, scripts/install.py (Python replacement for install.sh), scripts/templates/install/
• Update: setup.sh, scripts/commands/__init__.py