fix(sessions): Fix not copying URL from link-bubbles

[mp-hog]

Problem

Right-clicking a GitHub PR/issue chip in a conversation and choosing Copy did nothing, the clipboard kept its previous contents.

Two causes:

1. The context menu's "Copy" only read window.getSelection(). Right-clicking never creates a selection, and the chip (GithubRefChip, a Chip button) never exposed its URL — so there was nothing to copy.
2. Even with the URL captured, the write fired synchronously inside the Radix ContextMenu.Item onSelect, while the menu's focus scope is tearing down. In Electron/Chromium navigator.clipboard.writeText rejects with "Document is not focused" at that instant, leaving the old clipboard contents.

Fix

• GithubRefChip exposes its href via a data-github-ref-url attribute on a display:contents wrapper, discoverable from any right-click target (icon, label, chip root).
• The context menu captures that URL on right-click and copies it, falling back to the text selection, with success/error toasts.
• The clipboard write is deferred one task (copyFromContextMenu) so it runs after the menu closes and focus returns to the document.

Tests

• Unit tests for getGithubRefUrlFromEventTarget, resolveCopyText, and copyFromContextMenu (deferral + success/error callbacks).
• A GithubRefChip DOM-attribute test.
• An integration test driving the real right-click → Copy flow through a Radix ContextMenu with the real GithubRefChip.

pnpm --filter @posthog/ui exec vitest run \
  src/features/sessions/components/copyContextTarget.test.ts \
  src/features/sessions/components/copyContextMenu.integration.test.tsx \
  src/features/editor/components/GithubRefChip.test.tsx

Manual verification

• Verified manually by running the local build

🤖 Generated with Claude Code

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit c58bbe3.}

[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.

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### Issue 1 of 1
packages/ui/src/features/sessions/components/copyContextTarget.test.ts:54-68
**Prefer parameterised tests for table-driven cases**

The `resolveCopyText` and `getGithubRefUrlFromEventTarget` describe blocks each contain multiple `it()` calls with the same assertion shape and could be expressed more concisely as `it.each` tables. For example the three `resolveCopyText` cases are pure input → output pairs that map directly onto a data table. The same pattern applies to the four `getGithubRefUrlFromEventTarget` cases (the DOM setup can be hoisted outside the table).

_{Reviews (1): Last reviewed commit: "fix(sessions): copy PR/issue link from c..." | Re-trigger Greptile}

[greptile-apps]

_{Reviews (2): Last reviewed commit: "style(sessions): apply biome formatting" | Re-trigger Greptile}