fix(agent): match proceed and yes please proceed as explicit continuations

[Katsoragi]

Summary

Teaches the agent loop to recognize variations of "proceed" (e.g. "yes please proceed", "please proceed") as explicit user confirmations, keeping conversational context intact rather than misinterpreting them.

Target branch

• This PR targets dev, not main. All PRs land in dev; main is curated by the maintainer at each release. If your PR is on main by accident, click "Edit" on this PR and change the base.

Linked Issue

Fixes #5163

Type of Change

• Bug fix (non-breaking — fixes a confirmed issue)
• New feature (non-breaking — adds new behaviour)

Checklist

• I searched open issues and open PRs — this is not a duplicate.
• This PR targets dev
• My changes are limited to the scope described above — no unrelated refactors or whitespace changes mixed in.
• I actually ran the app and verified the change works end-to-end.

How to Test

Verify in chat that saying "yes please proceed" correctly moves to the next step.

Checks Run

• Run pytest suite: pytest tests/test_agent_loop.py (All Passed).