fix: Render at-mentioned chips as @labels in task titles

[charlesvien]

Problem

At-mentioned directories (and other chip types) rendered as raw XML like <folder path="products/agentic_tests" /> in task titles instead of human-readable text.

Closes #2172

Changes

1. Add xmlToPlainText helper composing xmlToContent + contentToPlainText
2. Use it in the task-creation saga so every chip type renders as @label
3. Drop unused createFileTagRegex import from the saga
4. Update attachment-only saga test (now shows @tmp/code.ts instead of "Reading attachment…")
5. Add folder-mention regression test plus xmlToPlainText unit tests

How did you test this?

Manually

Publish to changelog?

no

[charlesvien]

• fix: Preserve cloud reasoning level after initial prompt #2272
• fix: Unblock cloud branch picker during slow remote load #2269
• fix: Make file references in agent messages clickable in command center #2271
• fix: Render at-mentioned chips as @labels in task titles #2270 👈 (View in Graphite)
• fix: Buffer feature-flag subscribers registered before init #2267 : 1 other dependent PR (#2268 )
• feat: Add nightly cleanup of stale draft releases #2239
• main

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[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
apps/code/src/renderer/features/message-editor/utils/content.test.ts:200-241
**Prefer parameterised tests for `xmlToPlainText`**

The six new `it(...)` blocks all follow the same `xmlToPlainText(input) → expected` shape and should be collapsed into a single `it.each` table per the team's stated simplicity rule. Additionally, they are placed inside `describe("xmlToContent")` rather than their own `describe("xmlToPlainText")` block, which makes the test output misleading. The `github_pr`/`github_issue` test (lines 224-235) also packs two unrelated cases into one `it`, which hides which case fails on a first run.

_{Reviews (1): Last reviewed commit: "polish chip-aware title refactor" | Re-trigger Greptile}

[graphite-app]

Merge activity

• May 21, 7:55 AM UTC: Graphite rebased this pull request, because this pull request is set to merge when ready.
• May 21, 11:36 AM UTC: Graphite couldn't merge this PR because it failed for an unknown reason (GitHub is reporting that this PR is not mergeable, despite passing required status checks defined by your branch protection rules. Please check your rulesets for additional blocking criteria. Graphite Merge Queue does not currently support rulesets. Please contact Graphite support for further assistance.).