feat(tui): widen nav sidebar so labels do not wrap

[pedrofuentes]

Summary

NAV_WIDTH.expanded 14→24 + navWidth in LayoutPlan; AppShell pins the nav box width + flexShrink:0 so 'Conversations'/'Debates' render on one line; verified no overflow at 120/140 cols; Phase 11 polish — feedback #7

Changes

• src/tui/lib/breakpoints.ts: NAV_WIDTH.expanded bumped from 14 → 24 (fits ● 💬 Conversations 18 cols + paddingX 2 + border 2 = 22 minimum; 24 adds breathing room). New navWidth: number field added to LayoutPlan interface; computeLayout exposes it as NAV_WIDTH[navState].
• src/tui/components/layout/AppShell.tsx: nav <Box> now receives width={props.layout.navWidth} and flexShrink={0} so the nav pane is fixed-width and cannot be squeezed by the main pane's flexGrow={1}.

Tests

• breakpoints.test.ts: new assertions for navWidth (expanded=24, rail=3, hidden=0) and updated mainWidth === columns - navWidth
• app-shell.test.tsx: new test renders AppShell with ● 💬 Conversations in the nav and asserts the label is on one line (emoji and text not split), frame ≤ rows lines

Full TUI suite: 901 tests pass. Lint zero. Typecheck clean.

[pedrofuentes]

Status: CONDITIONAL

Sentinel Review Report

Ref: feature/tui-nav-width → main
Report ID: SENTINEL-1755-a48224a
Reviewed SHA: a48224a
Sentinel ruleset: v1
Reviewed at: 2026-06-26T10:37:34-07:00
Mode: standard
Review depth: Tier 2 (full)
Required action: FILE_ISSUES_AND_MERGE

Phase 1 — TDD / Test Evidence

• Tests exist & meaningful: ✅ tests/unit/tui/breakpoints.test.ts:66-75 asserts navWidth for expanded/rail/hidden and mainWidth; tests/unit/tui/app-shell.test.tsx:190-212 renders AppShell and asserts the Conversations label remains with the emoji on one line.
• Test-first history verified: ✅ git log --oneline origin/main..origin/feature/tui-nav-width → 4db25c0 test(tui): add failing tests for wider nav sidebar precedes a48224a feat(tui): widen nav sidebar so labels do not wrap; git show --name-status 4db25c0 touched only test files, and git show --name-status a48224a touched only source files.
• RED verified: ✅ at 4db25c0, npx --yes pnpm@10.30.1 exec vitest run tests/unit/tui/breakpoints.test.ts tests/unit/tui/app-shell.test.tsx --reporter=dot failed as expected: Test Files 2 failed (2) / Tests 3 failed | 16 passed (19), including expected undefined to be 24 at app-shell.test.tsx:193 and breakpoints.test.ts:68.
• Full suite green on SHA: ✅ at a48224a, npx --yes pnpm@10.30.1 test -- --reporter=dot → Test Files 358 passed | 1 skipped (359) / Tests 4519 passed | 1 skipped (4520).
• Required targeted verification: ✅ npx --yes pnpm@10.30.1 exec vitest run tests/unit/tui → Test Files 95 passed (95) / Tests 901 passed (901); npx --yes pnpm@10.30.1 lint exit 0; npx --yes pnpm@10.30.1 typecheck exit 0.
• Coverage: N/A (no coverage gate/output required for this PR).
• Branch base: ✅ git merge-base origin/main origin/feature/tui-nav-width = 4cf1b8c610c6f3f4e83d0cf692624568c4317add (current origin/main).

Phase 1.5 — Fast-path Evaluation

🔴 count: 0 | LOC: 18 non-test/non-lockfile changed (≤150: Y) | Security paths: Y (terminal UI rendering surface) | New deps: N | Commit types qualify: N (feat)
→ Fast-path eligible: NO → Phase 2

Phase 2 — Execution Log

Dim	Tool Call	Agent ID / Ref	Status
A1	task(agent_type="general-purpose", name="sentinel-dim-a1")	N/A (Copilot task returned inline result; no stable ID exposed)	✅ No findings
A2	task(agent_type="general-purpose", name="sentinel-dim-a2")	N/A (inline result)	✅ No findings
B	task(agent_type="general-purpose", name="sentinel-dim-b")	N/A (inline result)	✅ No findings
C	task(agent_type="general-purpose", name="sentinel-dim-c")	N/A (inline result)	✅ No findings
D	task(agent_type="general-purpose", name="sentinel-dim-d")	N/A (inline result)	✅ One test-quality finding
E	N/A	N/A	✅ N/A (no dependency/supply-chain surface changed)
F	task(agent_type="general-purpose", name="sentinel-dim-f")	N/A (inline result)	✅ One minor documentation/comment finding
Persist	gh pr comment 1755 --body-file -	PR #1755 comment	✅ Full report posted

Additional checks: git diff --check origin/main...origin/feature/tui-nav-width exit 0. Scope confirmed limited to breakpoints.ts, AppShell.tsx, and their tests.

Findings

• 🔴 CRITICAL: 0
• 🟡 IMPORTANT: 1 new / 0 known
• 🟢 MINOR: 1

Details (ordered by severity)

1. 🟡 IMPORTANT — AppShell regression test can pass without the fixed-width nav Box — packages/cli/tests/unit/tui/app-shell.test.tsx:210-212

   • Evidence: const conversationsLine = lines.find((l) => l.includes("Conversations")); / expect(conversationsLine).toBeDefined(); / expect(conversationsLine).toContain("💬");
   • Why: The source change at packages/cli/src/tui/components/layout/AppShell.tsx:86-87 is width={props.layout.navWidth} and flexShrink={0}, but the test only checks the synthetic label remains on one line; Ink can still size the nav to this short content even if width={layout.navWidth} is removed.
   • Impact: Trigger: a future regression removes or stops honoring fixed nav width. Mechanism: the current test still passes because it does not assert the nav pane width or create enough layout pressure to require flexShrink={0}. Consequence: the original wrapping UX bug can recur while CI remains green.
   • Remediation: Add an assertion that observes the nav pane occupying layout.navWidth columns (or render under pressure where removing width/flexShrink={0} reproduces wrapping) so the test fails when AppShell stops applying the fixed nav width.

2. 🟢 MINOR — RED-phase comment is stale on the final green commit — packages/cli/tests/unit/tui/app-shell.test.tsx:192

   • Evidence: // RED: navWidth does not yet exist on LayoutPlan
   • Why: On final HEAD, navWidth does exist, so the comment describes historical TDD state rather than current behavior.
   • Impact: Minor maintainer confusion when reading the final test.
   • Remediation: Remove the comment or replace it with a behavior-focused rationale.

Follow-ups & Actions

• CONDITIONAL → FILE_ISSUES_AND_MERGE: file GitHub issues for the new 🟡 and 🟢 findings (sentinel:important, sentinel:minor), link them in PR feat(tui): widen nav sidebar so labels do not wrap #1755, then merge if policy permits.
• ⚠️ Do NOT fix 🟡/🟢 findings in this PR — file as issues only.
• Only 🟡/🟢 findings remain; there are no 🔴 blockers.

Decision rationale

• Verdict: CONDITIONAL for reviewed SHA a48224a69bc3595b58da49f24940a3de4cbfa216.
• TDD ordering and commit purity are compliant: test-only commit first, source-only implementation commit second.
• RED/GREEN evidence exists, targeted TUI suite/lint/typecheck pass, and the full package test passed on final SHA.
• Width math is internally consistent: expanded=24, rail=3, hidden=0; mainWidth = max(0, columns - navWidth) prevents negative widths at small/override sizes and preserves tooNarrow behavior.
• The remaining issue is a non-blocking test-quality gap; per Sentinel rules, new 🟡 findings produce CONDITIONAL rather than REJECTED.

[pedrofuentes]

Sentinel SENTINEL-1755-a48224a → CONDITIONAL (0 🔴). Follow-ups filed: #1759 (🟡 test coverage), #1760 (🟢 stale comment). Merging per CONDITIONAL policy.