Show cloud artifact PRs in prompt chip

[kevinchevalier]

Description

Show GitHub PR artifacts from cloud agent sessions in the terminal prompt PR chip when the artifact can be associated with the cloud session's current working directory.

This adds a client-side enrichment pass for static shared-session prompt snapshots: PR artifacts are matched by repo path segment in the prompt cwd and by the prompt git branch when available. If exactly one artifact PR matches, the existing GitHub PR chip is populated with that PR URL; if multiple PRs match, the chip is cleared to avoid showing an ambiguous PR.

Linked Issue

• The linked issue is labeled ready-to-spec or ready-to-implement.
• Where appropriate, screenshots or a short video of the implementation are included below (especially for user-visible or UI changes).

Slack thread: feedback-app message 1779209895.191109

Testing

• cargo fmt --manifest-path /workspace/warp/Cargo.toml --all --check
• cargo check --manifest-path /workspace/warp/Cargo.toml -p warp
• cargo test --manifest-path /workspace/warp/Cargo.toml -p warp context_chips::cloud_artifact_pr
• cargo clippy --manifest-path /workspace/warp/Cargo.toml -p warp --all-targets --tests -- -D warnings
• ./script/wasm/bundle --channel oss --nouniversal --check-only
• I have manually tested my changes locally with ./script/run

Note: I also tried cargo clippy --manifest-path /workspace/warp/Cargo.toml -p warp --all-targets --all-features --tests -- -D warnings, but that path failed because bundled channel config JSON files were not generated in this sandbox. The repo presubmit-style app clippy command above passed.

Screenshots / Videos

Not included; this is covered by unit tests around prompt snapshot enrichment and compile checks.

Agent Mode

• Warp Agent Mode - This PR was created via Warp's AI Agent Mode

CHANGELOG-OZ: Show GitHub PR artifacts from cloud agent sessions in the terminal prompt PR chip when they match the current cwd.

Co-Authored-By: Oz oz-agent@warp.dev

Conversation: https://staging.warp.dev/conversation/b3b14e56-04c1-4c1a-8ae3-1089eada11a4
Run: https://oz.staging.warp.dev/runs/019e412c-852b-7568-b596-6dd7f29115fb
This PR was generated with Oz.