Indicate when file in code mode is empty - don't show a syntax error

[jurgenwerk]

This PR addresses two issues:

• When viewing blank files in code mode, it removes the "Syntax error" display - this is not really a syntax error so we can just say the file is blank and that the module inspector tools are unavailable for that
• We will soon add a feature where if you are in interact mode and the assistant begins to create a file, it will currently switch you to code mode and open the index card, which is not a very good user experience - here we'll change this so that it first creates a blank file, switches to code mode and navigates to it, then starts generating the content. So in this case we'll show the "File is empty - the content is currently being generated by the AI Assistant" (last image below)

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Note

Improves empty-file UX in code mode and reflects AI generation status tied to recent assistant patches.

• Replaces SyntaxErrorDisplay for empty files with a centered message; shows "content is being generated by the AI Assistant" when the latest assistant message targets the file (streaming or ready patch), and hides it if canceled
• Adds generation detection logic in module-inspector.gts by inspecting Matrix room messages, author, streaming state, code patch readiness, and per-room canceled action tracking
• Introduces per-room cancellation tracking in matrix-service.ts (markActionAsCanceled, getLastCanceledActionEventId) and wires it from matrix/room.gts cancelActionBar
• Adds/updates acceptance tests to cover streaming, pending-acceptance, and cancel flows; updates schema-editor test to expect the new empty-file message

^{Written by Cursor Bugbot for commit d5091e3. This will update automatically on new commits. Configure here.}

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Host Test Results

    1 files  ±  0      1 suites  ±0   1h 38m 55s ⏱️ - 39m 28s
1 874 tests +234  1 859 ✅ +248  15 💤 ±0  0 ❌  -  1 
1 889 runs  +235  1 874 ✅ +262  15 💤 ±0  0 ❌  - 14 

Results for commit d5091e3. ± Comparison against base commit 75067cd.

This pull request removes 1 and adds 235 tests. Note that renamed tests count towards both.

Chrome ‑ Global error: Uncaught TypeError: Failed to fetch at http://localhost:7357/assets/chunk.a0f1fa411c6f69fe7c73.js, line 150984  While executing test: Acceptance | index card home resolution > operator submodes: host submode uses hostHome and updates after edit 

Chrome ‑ Acceptance | Code patches tests: empty file shows generating content while streaming a new file patch
Chrome ‑ Acceptance | Code patches tests: empty file shows generating content while waiting for patch acceptance
Chrome ‑ Acceptance | Code patches tests: empty file stops showing generating content after canceling patch
Chrome ‑ Acceptance | index card home resolution > operator submodes: host submode uses hostHome and updates after edit
Chrome ‑ Integration | Store: added instance that was previously not saved will begin to auto save after being added
Chrome ‑ Integration | Store: an instance can be restored after a loader reset
Chrome ‑ Integration | Store: an instance can debounce auto saves
Chrome ‑ Integration | Store: an instance can live update thru an error state
Chrome ‑ Integration | Store: an instance live updates from indexing events for a code update
Chrome ‑ Integration | Store: an instance live updates from indexing events for an instance update
…

♻️ This comment has been updated with latest results.

[Copilot]

Pull request overview

This PR improves the user experience when viewing empty files in code mode by displaying a friendly message instead of a syntax error. It also adds intelligent detection to show when the AI Assistant is generating content for an empty file.

Changes:

• Replaced error display for empty files with a user-friendly "File is empty" message
• Added dynamic message updates to show "generating content in the AI Assistant..." when AI is actively creating content for empty files
• Implemented tracking of canceled actions in the matrix service to properly hide generating messages when patches are canceled

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
packages/host/tests/acceptance/code-submode/schema-editor-test.ts	Updated test to verify empty file message instead of syntax error display
packages/host/tests/acceptance/code-patches-test.gts	Added comprehensive tests for empty file scenarios including streaming, patch acceptance, and cancellation
packages/host/app/services/matrix-service.ts	Added canceled action message tracking with getter/setter methods and proper cleanup
packages/host/app/components/operator-mode/code-submode/module-inspector.gts	Implemented empty file detection and generating content logic with associated styling
packages/host/app/components/matrix/room.gts	Integrated canceled action tracking with the matrix service when user cancels actions

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

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