Add AutoPlayer bot, stage generator CLI, and calibrated Season 1 (60 stages)

Greedy bot with tray-survival lookahead and gem-line steering; generator
samples layouts along a difficulty curve, probes bot moves-to-win, sets
adaptive move budgets targeting win-rate bands, and derives star
thresholds from spare-move quantiles. Season 1 pack bundled in assets
with per-stage difficulty report.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

content/season_001/spec.json

@@ -0,0 +1,10 @@
+{
+  "seasonId": "season_001",
+  "version": 1,
+  "title": { "en": "First Bloom", "ko": "첫 개화" },
+  "theme": { "tileSet": "spring", "background": "background.webp" },
+  "stageCount": 60,
+  "baseSeed": 20260611,
+  "runsPerStage": 80,
+  "copyToAssets": "assets/seasons/season_001/pack.json"
+}