bug(resume): Codex picker can show no results while matching rollouts exist #718

Problem

The Codex Resume Session palette can display No matching sessions even though matching rollout JSONL files exist for the focused cwd and the production Codex lister returns them.

Evidence

For /Users/juliusolsson/Desktop/Development/agent-code/.worktrees/feat-codex-disk-trust, both the pre-restart and post-restart Codex rollouts exist under ~/.codex/sessions/2026/08/30. A direct call to the production lister returns both. The incident journal shows the renderer invoked session:list-for-cwd, but the visible resume palette showed no results.

Acceptance

• Resume listing records provider, normalized cwd, result count, and failure class without transcript content.
• A Codex-focused pane passes codex and its exact cwd through the palette and IPC boundary.
• Returned sessions render when the query is empty.
• Listing errors are distinguishable from a genuine zero-result list in diagnostics and UI.
• A regression test covers a matching Codex rollout whose session_meta line is larger than the historical byte-head limit.

Related: #96, #151.