Add design evolution system

[nahiyankhan]

Summary

• Evolves Ghost from drift detection into a design evolution observatory where drift is neutral signal, not regression
• Adds parent lineage system — any design system can be the parent (not just ghostui), declared via parent in config
• Adds acknowledgment commands (ghost ack, ghost adopt, ghost diverge) for human-in-the-loop intentional drift recording
• Adds temporal comparison (--temporal flag) with drift velocity, trajectory classification, and ack-aware bounds checking
• Adds fleet view (ghost fleet) for N-way ecosystem comparison with pairwise distances, centroid, spread, and clustering

New commands

Command	Purpose
ghost profile --emit	Publish .ghost-fingerprint.json as a referenceable artifact
ghost ack	Acknowledge current drift with per-dimension stance
ghost adopt <fp>	Shift parent baseline to a new fingerprint
ghost diverge <dim>	Declare intentional divergence on a dimension
ghost compare --temporal	Compare with velocity, trajectory, and ack status
ghost fleet <fp...>	Ecosystem-level N-way comparison

New modules

• evolution/parent.ts — resolve any ParentSource to a fingerprint (URL, path, package)
• evolution/emit.ts — publish .ghost-fingerprint.json
• evolution/history.ts — append-only .ghost/history.jsonl
• evolution/sync.ts — read/write .ghost-sync.json acknowledgment manifest
• evolution/temporal.ts — drift velocity and trajectory computation
• evolution/vector.ts — per-dimension embedding-space drift vectors
• evolution/fleet.ts — pairwise distances, centroid, spread, clustering
• reporters/temporal.ts + reporters/fleet.ts — CLI/JSON formatters

Also fixes pre-existing noAssignInExpressions lint error in values scanner.

Test plan

• pnpm build compiles cleanly
• pnpm test — all 24 existing tests pass
• pnpm check — biome lint, typecheck, file sizes all pass
• ghost profile --emit writes .ghost-fingerprint.json and appends to .ghost/history.jsonl
• ghost ack with a declared parent writes .ghost-sync.json
• ghost compare a.json b.json --temporal shows velocity and trajectory
• ghost fleet a.json b.json c.json shows pairwise distances and centroid

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