vein/web: evolve hill-climb chart + shareable deep links

[Evanfeenstra]

What

Two UI additions to the vein web app, motivated by watching a live gaia-evolve run:

Evolve hill-climb chart

A live SVG chart at the top of the events panel for any run containing an eval/evolve-loop step. Derived purely from the event stream — the loop already emits synthetic <path>#<gen> events whose output carries { gen, fitness, bestFitness, bestGen, directive, version, knownCost, runs }, so there are no engine or API changes.

• dashed baseline line + baseline anchor dot
• green best-so-far staircase (reads as a hill-climb, not a scatter)
• one dot per generation: filled green = new best, hollow blue = non-improving, amber stroke = explore directive, red ✕ = failed generation, pulsing = generation in flight
• dots click through to that generation's run (same run-ref plumbing as event rows), native tooltips with version/fitness/Δ/cost
• domain-agnostic: harvey-evolve and gaia-evolve both flow through the same step type

Shareable deep links

?wf=<workflow>&run=<runId>&v=<version> select on load, and the address bar tracks the selection via replaceState (no history spam; the existing ?chat param is preserved). Whatever is on screen is always a copy-paste shareable link, e.g.:

http://localhost:3355/lab/?wf=gaia-evolve&run=1787954224201

Testing

• tsc --noEmit clean in vein/web
• Verified live against an in-flight gaia-evolve run under /lab: deep link loads the run view directly and tails it; chart renders baseline 0.75 + pulsing pending dot for the running generation, updates as events stream in

🤖 Generated with Claude Code