feat(advisor): TUI settings write surface — tuiSettingsSections Advisor section (dsh-tui /settings)

[btspoony]

Iteration iter-20260817-dsh-advisor-n9

Adapt the advisor's settings to the new dsh-tui settings seam (tuiSettingsSections, shipped in dsh-tui v0.8.0 — upstream issue dsh-TUI#165/PR #238). This delivers the n8 Roadmap "Next" TUI settings write surface, this-repo only (zero dsh-TUI changes, zero new peers).

Deliverable

• src/tui-settings.ts — register an editable Advisor section on the tuiSettingsSections seam: fields enabled / provider / model / immuneTurns / maxDeltaMessages (zh/en labels + hints). systemPrompt is intentionally NOT a TUI field (single-line input truncation risk — edited via the web card / $DSH_HOME/settings.yaml). Shared TUI_SETTINGS_SECTIONS service-key constant drives both the registration and the /advisor config hint probe. Conditional inject → clean no-op on dsh-tui < v0.8.0 / non-TUI hosts; multi-fiber duplicate-ns contained; registered only on the single-reviewer (claiming) fiber.
• src/commands.ts + src/index.ts — /advisor config stays a session-less read-only readback; its edit hint is now truthful: lists the TUI /settings screen (Advisor section) when the seam is mounted, else the n8 text.
• README + docs — corrected every "TUI has no settings page / no write command" claim; documented the three parallel edit paths (TUI /settings, profile patch, shared $DSH_HOME/settings.yaml), the systemPrompt exclusion, the web-card-vs-TUI save-behavior difference (S4 explicit model gate still resolves disabled-with-reason), and the dsh-tui ≥ v0.8.0 requirement.

Gates

• SDD T1–T3 + task reviews (Approve ×3) on iteration/iter-20260817-dsh-advisor-n9 (base = current main).
• QC tri: Approve ×3 (0C/0W/6S) → zero-residual fix wave b2e0381 → targeted re-review Approve ×3 — Approve clean, no open R#.
• QA mandatory: PASS-with-gaps @ b2e0381 — AC-1..AC-6 deterministic PASS (real dsh-settings-file write path 3→5 / 60→100 lands in the settings.yaml user layer + live re-apply; schema backstop 2.5 / -1 rejected whole-save nothing stored; both hint branches byte-exact; /advisor status/config live; web profile intact; typecheck / 377 tests / build green). Residuals R1–R6 = interactive human spot-checks (PTY blocked in the QA sandbox) — recorded in qa.md.
• Iteration close: compound refreshed dsh-tui-plugin-client-surface.md for the post-#165 seam (S1–S6 stale claims corrected); compass completed + end_date; close gate PASS.

PR merge remains manual (not auto-merge). In a real dsh-tui v0.8.0 terminal: dsh --profile dsh-tui → /settings → edit the Advisor section → save → /advisor config reflects the change.