Remove max_repair_rounds plumbing

[zhongkaifu]

Motivation

• The planner no longer exposes a configurable max_repair_rounds surface, so call sites and docs that passed or referenced this parameter were removed to keep the API consistent.
• Simplify CLI and example scripts by relying on the planner's internal repair behavior rather than plumbing an external round limit.

Description

• Removed the --max-repair-rounds CLI argument and stopped passing max_repair_rounds into update_workflow_with_two_pass in update_workflow.py.
• Removed max_repair_rounds arguments passed from example and server code by updating build_workflow.py and webapp/server.py to call plan_workflow_with_two_pass / update_workflow_with_two_pass without the deprecated parameter.
• Updated tests/test_update_workflow_planner.py to match the new planner signature and revised the README text to drop the max_repair_rounds reference.

Testing

• No automated tests were executed as part of this change (tests were updated to reflect the API change but test suite was not run).

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Codex Task