feat: filter review output to P0/P1 findings only

[varin-nair-factory]

Summary

Restores P2/P3 priority levels for internal categorization while filtering review output to only post P0/P1 findings.

Changes

• Added P2 and P3 priority level definitions back to the review prompt
• Added explicit instruction to only post P0/P1 findings as inline comments
• P2/P3 findings are suppressed to reduce review noise from minor issues
• Updated output format to reflect P0/P1 only

Context

PR #13's review flagged a trivial array allocation as P1, which was too aggressive. By having P2/P3 available for categorization but filtering them from output, the droid can properly classify minor issues without cluttering the review with noise.

[factory-droid]

Droid finished @varin-nair-factory's task —— View job

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[factory-droid]

Overall: looks correct. This PR only updates the review prompt instructions (adds P2/P3 definitions and clarifies that only P0/P1 should be posted as inline comments), and I didn’t find any bugs introduced by the change.