feat(enrichment): long-file / big-function heuristic analyzer

[JSONbored]

New REES local analyzer that flags size/altitude smells structurally: a changed file whose new length exceeds a threshold, and functions whose body (brace/indent span) added in the diff exceeds a line threshold. Reviewer signal for maintainability, distinct from cyclomatic complexity (bundled into #1477). Pure compute, no network — length can be computed from patch hunks + additions.

Deliverables

• Add SizeSmellFinding ({ file, line?: number, kind: 'long-file'|'big-function', measure: number, threshold: number, name?: string }) + sizeSmell? key to review-enrichment/src/types.ts
• Create review-enrichment/src/analyzers/size-smell.ts: estimate new file length from patch hunk headers/additions; scan added lines for function declarations and estimate body length by brace/indent balance; configurable maxFileLines/maxFunctionLines limits; cap findings
• Register a local descriptor (category 'quality', cost 'local', requires ['files']) with inline render() in review-enrichment/src/analyzers/registry.ts
• Add review-enrichment/test/size-smell.test.ts covering long-file threshold, big-function detection, sub-threshold clean case, and the finding cap

References

• review-enrichment/src/analyzers/actions-pin.ts (hunk header parsing for line numbers/length)
• review-enrichment/src/analyzers/registry.ts:158-175 (limits object shape)
• review-enrichment/src/types.ts:289-311

Part of #1499.

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size: S · gittensor:feature

[linear-code]

JSO-2136