fix(web): agent tool button height

[ilteoood]

Summary

• Base branch: master (all contributions)
• What changed and why:
  • the original button height as not taking care of the whole available space
  • I applied a single CSS class to set the whole button to be full height, independently to its content
• Scope boundary: (what this PR explicitly does NOT change) everything but web
• Blast radius: (what other subsystems or consumers could be affected) agent tools on web
• Linked issue(s): Closes [Bug]: Agent tools button behaviour on hover #6368

Validation Evidence (required)

cargo fmt -> exit code 0
cargo clippy -> Finished dev profile [unoptimized + debuginfo] target(s) in 52.05s
cargo test -> exit code 0

Manually tested

Security & Privacy Impact (required)

Yes/No for each. Answer any Yes with a 1–2 sentence explanation.

• New permissions, capabilities, or file system access scope? (No)
• New external network calls? (No)
• Secrets / tokens / credentials handling changed? (No)
• PII, real identities, or personal data in diff, tests, fixtures, or docs? (No)
• If any Yes, describe the risk and mitigation:

Compatibility (required)

• Backward compatible? (Yes/No) Yes
• Config / env / CLI surface changed? (Yes/No) No
• If No or Yes to either: exact upgrade steps for existing users: No steps

Rollback (required for risk: medium and risk: high)

Low-risk PRs: git revert <sha> is the plan unless otherwise noted.

---

Labels live in the GitHub label UI, not in the body. Set risk:*, size:*, and scope labels via the sidebar. Auto-label corrections: add risk: manual and the intended label.

Commit trailers capture AI-assisted collaboration (Co-Authored-By: Claude ...) — no separate section needed.

Privacy contract (docs/book/src/contributing/privacy.md) is a merge gate. Never commit real identities, secrets, personal emails, or PII in diff, tests, fixtures, or docs.

[singlerider]

Title needs a scope to match the repo convention. Every other PR uses type(scope): description -- yours is missing the scope.

Change it to something like:

fix(web): agent tool button height

You can edit the title directly on the PR page.

Also worth strengthening the PR body before this gets reviewed:

• Validation Evidence is thin. The template asks for literal command output, not just "Manually tested" + screenshot. Even for a CSS-only change, paste your cargo fmt, cargo clippy, and cargo test output, or explicitly state why each was skipped.
• Summary could use one more bullet explaining why the height was wrong and what the fix does, not just what changed.