feat(review): multi-line ```suggestion blocks via RIGHT-side range validation

[JSONbored]

Support multi-line suggested changes: a finding may carry a start/end line range that maps to a GitHub multi-line inline comment with a ```suggestion block spanning the range. Depends on the single-line render + anchor-safety slices; validates the whole contiguous range is commentable before emitting.

Deliverables

• Add optional endLine? (or a startLine/line pair) to InlineFinding (src/services/ai-review.ts:215) + parser (src/services/ai-review.ts:414)
• Extend ReviewInlineComment (src/review/inline-comments.ts:38) to carry start_line/start_side for GitHub multi-line comments
• In selectInlineComments, require EVERY line in [start,end] to be in rightSideLinesFromPatch; else downgrade to the single anchored line (no 422)
• Tests: full-range valid, partial-range invalid → downgrade, inverted range guard, single-line still works, all branches

References

• src/review/inline-comments.ts:38
• src/review/inline-comments.ts:79
• src/services/ai-review.ts:215
• part of #1956

Part of #1956.

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size: S · held for later release (gittensor:feature once activated)

[linear-code]

JSO-2243