fix(sessions): preserve conversation across reconnects

[richardsolomou]

Problem

Local and worktree tasks could reconnect with a fresh native agent session while the UI still showed the previous transcript. The replacement agent received none of that history, so it appeared to forget the conversation.

Changes

I restore persisted conversation history when native resume is unavailable, preserve it across transient prompt failures, and avoid resending history after a successful native resume. Claude hydration now returns the selected conversation so the fallback can reuse it without downloading the logs twice.

How did you test this?

• Ran 45 workspace-server agent tests.
• Ran 64 Claude JSONL hydration tests.
• Ran Agent and workspace-server typechecks, the Agent build, Biome, and diff checks.

Automatic notifications

• Publish to changelog?
• Alert Sales and Marketing teams?

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[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 0c1cf9c.}

[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(sessions): preserve conversation acr..." | Re-trigger Greptile}