feat: wire M2 long-document (outline approval + >30k batching) into the live HTML-export wizard

[project820]

Context

The R1 HTML-export cutover (#9, PRs #10–#23) shipped the LLM-authored direct engine and removed the legacy JSON renderer. The single-pass direct-authoring path is live.

The R1 scope also listed the M2 long-document workflow (outline approval UI + >30k approved-outline batching + one-section repair + confirmed partial export). Those building blocks were implemented as pure modules during R1 (html-export-outline.ts, html-export-batch.ts, buildOutlinePrompt / buildSectionPrompt in html-export-direct-prompt.ts) but were not wired into the live wizard at cutover.

As a safe interim (PR #24), documents whose source exceeds the 30,000-char single-pass boundary now fail fast with a localized "too long for single pass" message instead of firing a doomed single prompt that failed downstream as pipeline-oversize.

Deliverable

Wire the built M2 long-document path into the live wizard so >30k documents export via outline approval + batched section authoring instead of failing fast:

• surface the outline approval UI (createOutlineDraft → reorder/delete/edit/add → approveOutline) in the wizard when coverage.withinSinglePass === false
• main-side section transport + assembly for batchAuthorOutline (per-section generate → sanitize → resolve, then finalize the assembled document)
• coverage-gap handling: one section repair, explicit placeholder, confirmed partial export (per M2b)
• extend the direct harness with a long-document (>30k) batched-export case

Non-goals

• M3 prescan/recommendations, M4, M5 (explicit R1 deferrals, unchanged)

Acceptance

• A >30k-char document reaches the outline approval step, and after approval exports a finalized single-file HTML through the batched path with full source coverage (no silent omission, no pipeline-oversize failure).
• test:html-export-direct gains a passing >30k batched case.

[project820]

🤖 Grok PR-review bot

ℹ️ TRIAGE — M2 outline/batch modules exist, but the live wizard still fail-fasts >30k documents.

Summary

R1 shipped single-pass HTML export. html-export-outline.ts and html-export-batch.ts (plus unit tests) are on main. The wizard still treats withinSinglePass === false as an error and does not open outline approval. Wiring those modules into the live path is the remaining deliverable. No >30k export was executed this session (Unverified).

Reproducibility & Evidence

• Measured present: src/renderer/html-export-outline.ts, src/renderer/html-export-batch.ts, src/__tests__/html-export-outline.test.ts, src/__tests__/html-export-batch.test.ts
• Measured src/renderer/html-export-wizard.ts: if (!built.withinSinglePass) { dispatch({ type: 'AI_ERROR', error: t('he.error.tooLongSinglePass') }); return; } with comment that outline/batch is deferred
• Measured src/renderer/i18n/en.ts: he.error.tooLongSinglePass — “too long for single-pass HTML export (over 30,000 characters)”
• Measured src/renderer/html-export-direct-prompt.ts: withinSinglePass is the route flag; prompt builder does not silently drop the tail
• Unverified: test:html-export-direct current status; live wizard click-through on a >30k file

Impact & Priority Suggestion

🟠 P2 Med (suggestion only — not a verdict) — >30k sources cannot finish HTML export in the live wizard. Fail-fast is safer than a doomed single prompt (pipeline-oversize), but the M2 building blocks are unused. Not P0: no secret/CI/data-loss path; documents under the cap still export.

Duplicates & Related

• no known duplicate of “wire M2 into the wizard”
• Sibling HTML-export issues HTML export: descendant root-identity selectors (.dark .card / #app / [dir]) don't match after root-identity transfer — needs inner root-proxy #33 / HTML export: single-element-wrapped narration can still clear the #27 structural floor (element-floor residual) #34 / [P3 follow-up] keyframe validation/real-pass counter divergence at degenerate scale (>2000 rules) #58 are different residuals, not this wiring gap
• Non-goals M3–M5 remain out of scope

Next Evidence Needed

• Wizard branch: coverage.withinSinglePass === false → outline UI (createOutlineDraft → approve) instead of AI_ERROR
• Main-side batchAuthorOutline transport + assemble + one-section repair / confirmed partial export
• test:html-export-direct case for a >30k batched export (not run this session)
• Keep the structural gate and asset allowlist unchanged while wiring

ℹ️ TRIAGE