fix(docs): keep navbar brand fully visible at 1280px

[phodal]

Summary

The docs navbar now shows the full Better Harness brand at 1280px laptop widths instead of Better Har….

Why

• Issue/Story: [Bug]: Navbar brand truncated to “Better Har…” at 1280px desktop width #133
• User or maintainer outcome: The product name stays fully readable on common laptop widths without hiding Docs, Inspector, Blog, or search.

Traceability and Scope

• Spec/ADR, if applicable: docs/specs/2026-09-02-133-docs-navbar-brand-truncation.md
• Acceptance criteria addressed: AC-1 through AC-5
• Canonical owners changed: none
• Explicit non-goals: no Infima-to-Studio redesign; no hamburger at 1280px; no 996px breakpoint change

Change Type

• Bug fix

Test and Review Evidence

Check	Result
npx vitest run test/docs-navbar-brand-truncation.test.mjs	2 passed
npx vitest run test/skills-docs/doc-link-graph.test.mjs	8 passed
Playwright at 1280×800 / 1366×768 / 1024×768 / 390×844	Brand text Better Harness, scrollWidth <= clientWidth

Manual or visual evidence:

Playwright against http://127.0.0.1:3000/better-harness/. Desktop links remain at 1280px; hamburger remains at 390px. No console errors. Screenshots saved locally under .qoder/design-qa/docs-navbar/ (gitignored).

Risk and Recovery

• Compatibility and cross-platform impact: CSS-only docs theme override.
• Package, plugin, schema, or generated-file impact: none.
• Rollback or recovery path: revert this commit.
• Residual risk or unverified boundary: very crowded translations longer than English Better Harness were not measured.

AI Involvement

• Level: Generated
• Human review and validation: focused Vitest plus Playwright computed-style checks.

Checklist

• I followed AGENTS.md, CONTRIBUTING.md, and the relevant canonical-owner guidance.
• The change is focused and does not include unrelated local or generated state.
• Tests and documentation match the behavior actually delivered.
• Markdown links were checked when documentation moved or changed.
• Cross-platform behavior was considered for Windows, macOS, and Linux.
• Package/runtime verification was run when shipped files or dependencies changed.
• User-facing or compatibility changes are recorded in CHANGELOG.md.
• I have the right to contribute this work under the repository's MIT License.

Closes #133