feat(hangul): import, edit, and export HWP/HWPX

[seonghobae]

Closes #319 when this Draft satisfies all applicable exact-head gates and the release freeze permits integration.

Problem and scope

Inkspan needs local HWP/HWPX import, editing, and export without granting the library filesystem, network, credential, service, database, model, tenancy, or deployment authority. The implementation therefore keeps the document engine host-injected and projects only a bounded structural document JSON contract across the public package boundary.

Implemented slice

• Open HWP/HWPX bytes through a host-owned HangulDocumentEngine.
• Convert supported paragraphs, headings, text, bold, italic, and strike content into framework-neutral document JSON.
• Export edited document JSON as HWPX by default or legacy HWP explicitly.
• Enforce bounded source and output bytes and stable payload-redacted errors.
• Free host-engine documents through finally paths.
• Publish the /hangul package surface without requiring consumers to resolve TipTap declaration types.
• Include the usage guide, ADR, architecture/sequence documentation, package discovery, and regression coverage for the supported boundary.

This slice does not execute macros, scripts, links, or external relationships and does not acquire transport, persistence, authn/authz, tenancy, durable audit, migration, retention, credential, model/provider, or release authority.

Test-first and repair lineage

• 42bf1638d5e10a9b2d56e6a36866f0ef77bf194d defined the HWP/HWPX authoring contract before the implementation.
• f49b1a1adcb171d2193c016ed0dea68db9709e86 and 43d48779c2b5e475e5402346fdff88552b582811 introduced the bounded bridge and editable document behavior.
• c9290106ba222b318907abfb59e140a15d39351d removed unreachable nullish mark fallbacks that alone prevented the repository's 100% branch-coverage gate.
• c87be1f9ccbc456639ecdb65177cb2fa27e39b85 replaced the emitted @tiptap/core declaration dependency with a framework-neutral structural JSON contract so a strict standalone packed consumer can compile the /hangul subpath.
• RED — e25a93599d55fe8c34db73eb4ce67413443a72f6: added exact assertions that unsupported caller-controlled block and mark types must not be reflected in diagnostics.
• GREEN — 8d6e8754fc1db137cea2bb38e0819d271a821a26: changed those two diagnostics to fixed payload-redacted messages while preserving stable error codes.

Current contract

• Unsupported inline marks fail with UNSUPPORTED_DOCUMENT_MARK and a fixed message.
• Unsupported block nodes fail with UNSUPPORTED_DOCUMENT_NODE and a fixed message.
• Neither diagnostic includes the caller-controlled type value.
• Engine open/create failures, operation failures, invalid format, limits, and cleanup semantics remain stable.
• The public declaration remains independent of TipTap package declarations.

Exact-head evidence

Current exact head: 8d6e8754fc1db137cea2bb38e0819d271a821a26.

• CI 31763028607: successful.
• Security Scan 31763028698: successful.
• SAST Semgrep 31763028634: successful.
• OpenCode and Noema required-review workflows: successful on this exact head.
• Formal reviews: 0.
• Unresolved inline review threads: 0.
• Strix Security Scan 31763027808: still in progress and therefore not counted as passing.
• GitHub reports this Draft mergeable; that is not treated as authorization to integrate.

The live protected base is main@e8109ec2a17de8bd6594487aa12c8c8a93cb2c03. Any later head movement invalidates this exact-head evidence and requires fresh verification.

Integration and release boundary

Keep this PR Draft and unmerged while #118 freezes the protected v0.6.0 release candidate. Do not advance protected main, fabricate tag/release identity, or describe this next-release feature as shipped. Readiness requires the unchanged current head, completion of every applicable required workflow including Strix, zero valid unresolved findings, and release-order authorization.

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 47cc0ab3-bf27-4f8d-886b-4a7cdb1ed29d

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}