feat(llm-builtin): improve cell link serialization with @link format and any-schema handling

[seefeldb]

• Use @link format instead of / for cell link serialization to LLM tools
• Add @arrayEntry decorator for array elements that reference cells
• Handle any schema types by converting to cell links when appropriate
• Add base64 validation to prevent false positive link detection
• Add timeout handling for tool calls (30s timeout)
• Refactor chatbot.tsx to use patternTool helper for listMentionable
• Fix schema.ts to properly copy values before annotation to avoid mutations

---

Summary by cubic

Switches LLM tool serialization to the new "@link" format with smarter handling for any-schema and array entries to make responses clearer and safer. Adds tool call timeouts and includes schema in read responses.

• New Features

  • Serialize cell refs as {"@link": ...}; decorate array items with "@arrayEntry".
  • Convert values with any schema into links when they point to cells.
  • Output schema alongside read JSON.
  • Add 30s timeout for tool calls to avoid hanging executions.
  • Refactor chatbot listMentionable to use patternTool for simpler wiring.

• Bug Fixes

  • Copy objects/arrays before schema annotation to avoid mutations and fix seen cache tracking.
  • Return null for undefined read values and always clean up timers/sinks on tool execution.

^{Written for commit fb06802. Summary will update automatically on new commits.}

[cubic-dev-ai]

3 issues found across 5 files

Prompt for AI agents (all 3 issues)

Understand the root cause of the following 3 issues and fix them.


<file name="packages/runner/src/schema.ts">

<violation number="1" location="packages/runner/src/schema.ts:840">
When cloning the record before annotation, you also need to update the freshly pushed `seen` entry to point at the cloned value; otherwise future reads will return the outdated original object and lose the back-to-cell annotations.</violation>
</file>

<file name="packages/runner/src/builtins/llm-dialog.ts">

<violation number="1" location="packages/runner/src/builtins/llm-dialog.ts:1427">
handleRead now returns `{ type: &quot;json&quot;, value: serialized }` even when the cell value is `undefined`, so the tool response sends `{ value: undefined }`, which is not valid JSON and violates Anthropic&#39;s tool_result contract.</violation>

<violation number="2" location="packages/runner/src/builtins/llm-dialog.ts:1541">
`clearTimeout(timeout)` and `cancel()` aren’t wrapped in a `finally`, so any rejected tool call (including timeouts) leaves the timeout and result sink running, leaking resources and risking multiple resolves.</violation>
</file>

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