refactor(claude): make ctm pure-overlay; never mutate Claude config files

[aksOps]

Summary

ctm previously wrote three Claude-owned config files at install / first-run time:

• ~/.claude.json — remoteControlAtStartup=true
• ~/.claude/settings.json — tui="fullscreen", viewMode="focus"
• ~/.config/ctm/env.sh — sourced by the launching shell

This PR reduces ctm's footprint on Claude-owned config to zero. All ctm-side defaults are now delivered exclusively through:

• ~/.config/ctm/claude-overlay.json — passed to claude via --settings only when the session is launched through ctm
• ~/.config/ctm/claude-env.json — read by ctm at every spawn and exported into the launch shell as a Go-built export … prelude

Direct claude invocations (outside ctm) are now completely unaffected by ctm's preferences.

Changes

(1) Move UI / remote-control defaults into the overlay

• Add tui, viewMode, remoteControlAtStartup to buildSampleOverlay() in cmd/overlay.go.
• Delete:
  • claude.EnsureTUIFullscreen + EnsureViewModeFocus (mutated ~/.claude/settings.json)
  • claude.EnsureRemoteControlAtStartup + ClaudeJSONPath (mutated ~/.claude.json)
  • claude.patchJSONFile (no remaining callers)
  • All matching tests
• Drop the ensureClaude*Default helpers + call sites in cmd/bootstrap.go and cmd/install.go.

(2) Replace env.sh with claude-env.json

• New internal/config/claude_env.go:
  • LoadClaudeEnv(path) — strict JSON load with key-name validation
  • (ClaudeEnvFile).ShellExports() — alphabetised, single-quote-escaped export K1=V1 K2=V2 string
  • ClaudeEnvExports() — one-call convenience for the launch path
• BuildCommand's last param changes from envFilePath to envExports (a pre-built shell prelude).
• EnvFilePathIfExists and sampleEnvFile/writeEnvFile deleted.
• Sample claude-env.json pre-seeds CLAUDE_CODE_NO_FLICKER and CTM_STATUSLINE_DUMP (the same two vars the old env.sh shipped).

Backward compat

• claude.SettingsJSONPath + ReadEffortLevel are kept — read-only, used by the statusline renderer for the effortLevel field.
• Existing users: ctm auto-creates claude-env.json on next launch via ensureOverlaySidecars. Their stale ~/.config/ctm/env.sh becomes inert (per the hard-cutover plan; not auto-deleted).

Stats

17 files changed, +384 / −925.

Test plan

• go vet -tags sqlite_fts5 ./... — clean
• go build -tags sqlite_fts5 ./... — clean
• go test -tags sqlite_fts5 -race -count=1 ./... — all 27 packages pass
• CI: build-and-test, SonarCloud, CodeQL, Best Practices JSON Lint (no .bestpractices.json change so should no-op), Scorecard

Out-of-scope follow-up

internal/serve/server_extra_test.go:TestRunAdoptsUUIDsFromLogDir flaked once during local race-detector runs (2-second deadline polling tailer registration). Pre-existing — not touched by this PR. Worth quarantining or extending the deadline in a separate PR.

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
84.3% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud