Previously seeds carried hand-curated {category, target, initialHint}.
Now SEEDS is a flat string[] of keywords — at round-start, the model
generates {category, initialHint} on the fly. Benefits:
- adding a seed is trivial (just append a word)
- every round gets a fresh cryptic opener (varies across plays of the
same word)
- HINT STYLE rules apply to the opening hint too, so the initial clue
isn't a definitional giveaway
Implementation:
- prompts.buildStartRoundPrompt(target) — with good/bad examples
- ai-client.generateRoundStart(env, target) — same JSON-in-content
approach as judge(), with defensive fallbacks + redactSecret
- handlers.startFreshGame now async; surfaces roundstart errors via the
existing UPSTREAM_FAIL path
Tests: 449 pass (5 new for generateRoundStart, 1 for roundstart error path).