feat(code-reviews): incremental reviews on follow-up pushes

[alex-alecu]

Summary

On follow-up pushes, code reviews was starting completely from scratch — re-reading every file, re-analyzing everything. This PR adds incremental mode: when a previous completed review exists for the same PR, the agent gets the old summary + inline comments + previous HEAD SHA so it can git diff only what changed.

• New DB query findPreviousCompletedReview to find the last completed review SHA
• New incrementalReviewWorkflow prompt section in both GitHub and GitLab templates
• generateReviewPrompt swaps in the incremental workflow when conditions are met
• prepareReviewPayload checks the code-review-incremental feature flag, looks up the previous SHA, and passes it through
• Falls back to full review when: flag is off, no prior completed review, no summary comment, or force push broke history

Test plan

• Unit tests for generateReviewPrompt with and without previousHeadSha (7 new tests)
• Type check passes
• Lint passes
• Existing tests still pass
• Manual: create PR, push, wait for review, push again — verify incremental prompt is generated
• Manual: verify force push fallback works (agent falls back to gh pr diff)

[kilo-code-bot]

Code Review Summary

Status: 1 Issues Found | Recommendation: Address before merge

Overview

Severity	Count
CRITICAL	0
WARNING	1
SUGGESTION	0

Issue Details (click to expand)

WARNING

File	Line	Issue
src/lib/code-reviews/triggers/prepare-review-payload.ts	318	Incremental rollout uses the shared server-config-fetch distinct ID, so PostHog targeting applies globally instead of per owner.

Other Observations (not in diff)

Issues found in unchanged code that cannot receive inline comments:

File	Line	Issue
N/A	N/A	None.

Fix these issues in Kilo Cloud

Files Reviewed (7 files)

• src/lib/code-reviews/core/constants.ts - 0 issues
• src/lib/code-reviews/db/code-reviews.ts - 0 issues
• src/lib/code-reviews/prompts/default-prompt-template-gitlab.json - 0 issues
• src/lib/code-reviews/prompts/default-prompt-template.json - 0 issues
• src/lib/code-reviews/prompts/generate-prompt.test.ts - 0 issues
• src/lib/code-reviews/prompts/generate-prompt.ts - 0 issues
• src/lib/code-reviews/triggers/prepare-review-payload.ts - 1 issue

[kilo-code-bot]

WARNING: Incremental-review rollout is evaluated against a shared PostHog bucket

isFeatureFlagEnabled() defaults distinctId to 'server-config-fetch', so this call ignores the current review owner. Any percentage rollout or targeted rule for code-review-incremental will therefore turn incremental mode on for everyone or no one instead of the intended subset. Pass the same distinct ID you already use for code-review flags here.

Suggested change

	const incrementalEnabled = await isFeatureFlagEnabled(FEATURE_FLAG_INCREMENTAL_REVIEW);
	const incrementalEnabled = await isFeatureFlagEnabled(FEATURE_FLAG_INCREMENTAL_REVIEW, owner.userId);

[alex-alecu]

@Kilo fix it

[kilo-code-bot]

I couldn't apply this fix automatically this time.

The auto-fix run failed before it could push an updated commit.

Next steps:

• Retry with more guidance, or apply the fix manually.
• Session ID: agent_4ab0cb7c-0039-49da-a9ea-b4bd6a84015e

Technical details

Network connection lost.

[kilo-code-bot]

🤖 Auto-Fix Update

I successfully implemented changes to fix this issue, but encountered an error while creating the pull request:

Branch 'session/agent_4ab0cb7c-0039-49da-a9ea-b4bd6a84015e' does not exist on GitHub. The branch may not have been pushed yet. Please ensure the Cloud Agent successfully pushed the branch before creating a PR.

The changes are available on branch session/agent_4ab0cb7c-0039-49da-a9ea-b4bd6a84015e.