feat(tui): stream slug/preset installs through the wizard pipeline

[fullstackjam]

What does this PR do?

Makes install <slug> / install <preset> apply through the wizard's full-screen streaming pipeline instead of the linear "OpenBoot Installer / Step N" output — the real fix for "this UI is still old".

Why?

install <slug> resolves to a RemoteConfig and applied through installer.RunContext (linear). The earlier #143 unified runSyncInstall — a different path (the saved sync-source flow), which slug installs don't take. So the slug UI stayed old.

installer.ApplyContext is the same engine both the wizard and RunContext already use — only the reporter differs (ConsoleReporter vs the wizard's channel reporter). On a TTY we now resolve the plan with the linear pre-flight (installer.PlanForConfig: checkDependencies + Plan), then apply it via wizard.RunPipeline with a chanReporter. The installer's section headers ("Step 1: Git Configuration", "Step 4: Installation", …) already map to pipeline phases via the wizard's headerPhase, so it streams identically to the wizard.

• installer.PlanForConfig(cfg) — the RunContext flow up to (not including) apply.
• wizard.RunPipeline's run closure now receives an installer.Reporter; wizard.PhasesForPlan seeds the sidebar from an InstallPlan.
• runPipelineInstall wires it, mirroring the wizard's abort / screen-recording-reminder / save-sync-source handling.
• Non-TTY / --silent / --dry-run keep RunContext (linear) unchanged.

Testing

• go vet ./..., full internal/... suite, go test -race (wizard), make build — green
• TestPhasesForPlan locks the plan→sidebar mapping
• Verified on a real install <slug> in a tmux pty: renders the PIPELINE sidebar (✓ Git identity, ✓ Homebrew 24/24, ✓ Applications 18/18, ⠋ Dotfiles, …) + streaming log; zero "Step N" / "OpenBoot Installer" output

Scope

Covers every interactive TTY install that used RunContext — slug, preset, and file/RemoteConfig sources — so they all share the pipeline now. dry-run stays linear (shows what would happen).

Cross-repo checklist

• Docs/content update in openboot.dev? — No
• CLI ↔ server API contract change? — No

Notes for reviewer

• Builds on the fix(tui): repair sync pipeline hang, ctrl+c, hover, hit-test bounds #144 pipeline fixes (channel drain, ctx abort, race-free error handling) — same RunPipeline machinery.
• Pushed over HTTPS (gh token) — local SSH auth was down.

https://claude.ai/code/session_01HLoiSd2k9EJJ1HPjjDgUgo