feat(desktop): answer structured form interactions

[me2seeks]

Summary

• render Runtime Host-owned structured form interactions in the Desktop composer for both the main conversation and Side Chat
• preserve omitted optional fields separately from explicit empty or false values, while validating all six primitive field kinds through the shared core contract
• decode renderer responses at the IPC boundary and retire prompts only after Host settlement or its projected acknowledgement

Why

PR #4379 establishes the durable form interaction contract and Runtime Host continuation authority. Desktop still needs a surface adapter so a tool can collect bounded structured input without falling back to an untyped text question or inventing a second pending-interaction owner in the renderer.

This PR is stacked on #4379 and implements the Desktop slice of the rollout in #4364. It does not add provider-specific form state or change the MCP wire path.

Screenshots

Before, Desktop could only render the fixed question prompt. After, the same composer slot renders a structured form, preserves optional field intent, and reports field-local validation errors.

Before: fixed question prompt	After: structured form prompt

Usability states

Optional field included with explicit true	Field-local validation after submit

Test plan

• npm run build
• 122 focused UI/Desktop interaction tests
• 45 focused storage tests with a non-worktree temporary directory
• Storybook interaction check at 1440x900: defaults, optional boolean inclusion/value, invalid required string

Part of #4364.

[Astro-Han]

PR #4384 — 098cac3 — blind review sealed

Summary: Desktop structured-form answer surface stacked on #4379. Exact head 098cac3a547454b51cf0a37c36b775024583ddc9 frozen. Source is approvable with comments; inherits #4379's 2×P2+1×P3. No simplify finding. Full build passed; 91 focused Desktop/UI tests passed; exact-head hosted test green. 0 reviews/0 threads on stacked base; mergeable on stacked base.

Findings (reproducible):

• P2 — drafts reset on fields identity change — form resets drafts when fields array identity changes. Runtime Host recovery republishes same pending request as freshly projected objects; React DOM probe typed release-candidate, rerendered clone with same request ID → input became empty. Any pending-set change can trigger. Fix: reset only on stable requestId/semantic revision, add recovery regression.
• P2 — constraints not rendered — surface enforces minimum/maximum, length, cardinality, format but renders only generic invalid message. Production render of integer min=max=997 + date-time field contained neither 997 nor date-time, so legal opaque forms can be undiscoverably unanswerable. Fix: render visible/accessible constraint help and cover formats/ranges.

Gating: hosted test green on stacked base; full stack inherits #4379 risk. Direct current-main merge has explicitly ignored epoch conflict plus generated inventory conflicts (base stack not landed) — not retained as finding.

Automated review notice: This comment was posted by an automated review agent operated by AstroHan. It is not an independent human review and does not replace one.

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简体中文

本条结论来自 @捣蛋鬼 在 exact head 098cac3 的独立盲审，已按 @me2seeks 指示排除 compatibility epoch 冲突的计分。编排仅核对 head 未漂移与 CI 状态。

[me2seeks]

Fixed both findings in 28ad94a. Draft state is now keyed by requestId, so a recovery projection of the same request keeps local edits while a different request resets them. Field constraints are rendered visibly and linked to their field group through aria-describedby.

Added a DOM regression covering cloned fields, request replacement, ranges, formats, and accessible descriptions.

[me2seeks]

The previous CI failure was the renderer architecture ledger after the rebase, not a form test failure. This head refreshes that ledger and retains the form variant in the composer interaction union alongside main's Goal projection ownership. Local full build, renderer architecture check, UI form regression, and AppShell response regression pass.