Milestone D.2.6 — Enhanced code blocks

Status: Complete
Goal: D.2
Phase: 1.5 — Docs Site
Wave: 4
Estimated effort: 3 hours
ADR required: None

Spec detail: MASTER_BRIEF.md Part D (D.2.6).

---

Why This Milestone Exists

Quickstart and API docs are code-heavy. Default Shiki blocks lack filename strips, copy buttons, and line highlights expected in Vercel-quality docs.

D.3.3 quickstart mandates <CodeTabs> with curl/node/python — copy must work reliably and filenames must render for config snippets.

Shiki themes from D.2.1 must integrate against --panel without injecting conflicting backgrounds.

---

Non-Goals

• Runnable code playgrounds (Phase 2+)
• Syntax highlighting for non-code languages
• Diff view / line numbers on every block

---

Branch

feat/d2-6-code-blocks

PR Title

feat(docs): enhanced code blocks (D.2.6)

---

Prerequisites

• D.2.2 merged
• D.2.3 merged

---

Deliverables

• Copy button: lucide Copy → Check, 1.5s confirm, hover on pre
• Filename strip: ```text title="src/foo.ts" → 28px bar, mono filename
• Line highlight: ```ts {3,7-9} → bg-panel-raised + 2px accent left border

See MASTER_BRIEF Part D (D.2.6) for full acceptance detail.

---

Files Affected

---

Testing Requirements

• verifyCodeBlock_FilenameStrip: Block with title="…" renders filename bar
• verifyCodeBlock_CopyButton: Copy puts unhighlighted source on clipboard
• verifyCodeBlock_LineHighlight: Lines {3,7-9} show highlight in both themes

---

Acceptance Criteria

• Filename tab renders for blocks with title="…"
• Copy button works (clipboard contains unhighlighted source)
• Highlighted lines visible in dark and light without new colors

---

Risks