fix(training): correct stage-3 eval (locomotion-mask bugfix) and add grounded aggression stage

Re-ran stage-3 (curric-s3-no_draws vs curric-s2-defend) and the missing
stage-4 gate now that the locomotion-mask inference bugfix is in. Both
reverse or contradict the pre-fix bookkeeping: curric-s2-defend (grounded)
beats curric-s3-no_draws 60-26 and curric-s4-mechanics 57-24 when fairly
evaluated, so lifting the locomotion mask in stage 3 was a real regression
in floor play, not the improvement the buggy eval reported.

Adds a stage-5 "aggression" curriculum entry that resumes from stage 2
directly (via new resume_from_experiment/reference_experiment stage-dict
overrides in curriculum.py) instead of compounding the regression through
stages 3-4, keeps the locomotion mask on, and retunes ball-pursuit reward
weights for much more aggressive floor play. Extends train.py with the
three new --velocity-to-ball-weight/--ball-distance-penalty/--ball-touch-reward
flags needed to forward that retune to Godot's existing SHIP_AI_OVERRIDES.

curriculum_state.json and TRAINING.md are corrected/annotated in place
rather than silently rewritten, so the regression stays visible in history.

training/curriculum.py

@@ -80,6 +80,30 @@ STAGES = [
         "flags": [],
         "grounded": False,
     },
+    {
+        "name": "aggression",
+        # Deliberately resumes from stage 2 (curric-s2-defend), not stage 4
+        # (see resume_from_experiment/reference_experiment below) — the
+        # locomotion-mask inference bugfix (8c15c46) revealed that stage 3's
+        # full-3D unmask was a clear regression, not an improvement: fairly
+        # evaluated, curric-s2-defend beats both curric-s3-no_draws (26-60)
+        # and curric-s4-mechanics (24-57). Rather than compound that
+        # regression, this stage keeps the locomotion mask ON (matching
+        # stage 2's own regime) and just retunes ball-pursuit reward weights,
+        # so it can't reopen the same grounded-to-3D transition that caused
+        # the earlier failure. Full 3D flight is parked as a separate,
+        # later initiative.
+        "flags": [
+            "--opponent-mode", "self_play",
+            "--no-allow-vertical", "--no-allow-pitch-roll",
+            "--velocity-to-ball-weight", "0.05",   # up from 0.02
+            "--ball-distance-penalty", "0.006",    # up from 0.002
+            "--ball-touch-reward", "0.5",          # up from 0.4
+        ],
+        "grounded": True,
+        "resume_from_experiment": "curric-s2-defend",
+        "reference_experiment": "curric-s2-defend",
+    },
 ]
 
 
@@ -109,18 +133,31 @@ def resume_checkpoint(stage_index: int, attempt: int, seed_checkpoint: str | Non
         # work, so stage 1 starts from a random policy under its own
         # regime unless --seed-checkpoint says otherwise.
         return seed_checkpoint
-    prev_stage = STAGES[stage_index - 1]["name"]
-    prev_experiment = _passing_experiment_for_stage(stage_index - 1)
+    prev_experiment = _resume_source_experiment(stage_index)
     return str(TRAINING_DIR / "checkpoints" / prev_experiment / "final.zip")
 
 
 def reference_bot(stage_index: int) -> str:
     if stage_index == 0:
         return str(ROOKIE_REFERENCE)
-    prev_experiment = _passing_experiment_for_stage(stage_index - 1)
+    prev_experiment = _reference_source_experiment(stage_index)
     return str(TRAINING_DIR.parent / "Game" / "bots" / f"{prev_experiment}.json")
 
 
+# A stage normally chains off "whatever passed at the previous index," but a
+# stage can instead name an explicit resume_from_experiment/reference_experiment
+# to skip a since-regressed branch (see the "aggression" stage) without
+# rewriting history for the stages it's skipping past.
+def _resume_source_experiment(stage_index: int) -> str:
+    override = STAGES[stage_index].get("resume_from_experiment")
+    return override if override else _passing_experiment_for_stage(stage_index - 1)
+
+
+def _reference_source_experiment(stage_index: int) -> str:
+    override = STAGES[stage_index].get("reference_experiment")
+    return override if override else _passing_experiment_for_stage(stage_index - 1)
+
+
 def _passing_experiment_for_stage(stage_index: int) -> str:
     state = load_state()
     for entry in state["log"]:
@@ -129,6 +166,15 @@ def _passing_experiment_for_stage(stage_index: int) -> str:
     raise RuntimeError(f"No passing attempt recorded for stage {stage_index} ({STAGES[stage_index]['name']})")
 
 
+def _grounded_for_experiment(experiment: str) -> bool:
+    if experiment == "rookie":
+        return False
+    for index, stage in enumerate(STAGES):
+        if experiment_name(index, 0) == experiment:
+            return stage["grounded"]
+    raise ValueError(f"Unknown experiment for groundedness lookup: {experiment}")
+
+
 def run_stage_attempt(stage_index: int, attempt: int, args) -> str:
     exp = experiment_name(stage_index, attempt)
     resume = resume_checkpoint(stage_index, attempt, args.seed_checkpoint)
@@ -150,8 +196,10 @@ def run_stage_attempt(stage_index: int, attempt: int, args) -> str:
 
 
 def reference_grounded(stage_index: int) -> bool:
-    # rookie.json predates the locomotion mask entirely — always full 3D.
-    return False if stage_index == 0 else STAGES[stage_index - 1]["grounded"]
+    if stage_index == 0:
+        # rookie.json predates the locomotion mask entirely — always full 3D.
+        return False
+    return _grounded_for_experiment(_reference_source_experiment(stage_index))
 
 
 def evaluate_attempt(experiment: str, reference: str, episodes: int, stage_index: int) -> dict:

training/curriculum_state.json

@@ -1,5 +1,5 @@
 {
-  "stage_index": 3,
+  "stage_index": 4,
   "attempt": 0,
   "status": "in_progress",
   "log": [
@@ -40,16 +40,34 @@
       "experiment": "curric-s3-no_draws",
       "attempt": 0,
       "eval": {
-        "timestamp": "2026-07-21T20:46:34+00:00",
-        "model_a": "/home/jcreek/ai-training/CosmicClash/Game/bots/curric-s3-no_draws.json",
-        "model_b": "/home/jcreek/ai-training/CosmicClash/Game/bots/curric-s2-defend.json",
+        "timestamp": "2026-07-22T11:36:42+00:00",
+        "model_a": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s3-no_draws.json",
+        "model_b": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s2-defend.json",
         "episodes": 100,
-        "wins_a": 44,
-        "wins_b": 19,
-        "draws": 37,
-        "win_rate_a": 0.44
+        "wins_a": 26,
+        "wins_b": 60,
+        "draws": 14,
+        "win_rate_a": 0.26
       },
-      "decision": "pass"
+      "decision": "fail",
+      "note": "Original eval (44-19, recorded 2026-07-21T20:46:34) predates the locomotion-mask inference bugfix (8c15c46) and ran with the grounded stage-2 reference unfairly unmasked. Re-run post-fix with --grounded-b reverses the verdict: stage 3's full-3D unmask is a clear regression from stage 2, not an improvement. Not retried via the normal flag-retry mechanism — see stage_index 4 (aggression), which redirects around this branch by resuming from curric-s2-defend directly instead."
+    },
+    {
+      "stage_index": 3,
+      "experiment": "curric-s4-mechanics",
+      "attempt": 0,
+      "eval": {
+        "timestamp": "2026-07-22T11:38:57+00:00",
+        "model_a": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s4-mechanics.json",
+        "model_b": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s3-no_draws.json",
+        "episodes": 100,
+        "wins_a": 26,
+        "wins_b": 33,
+        "draws": 41,
+        "win_rate_a": 0.26
+      },
+      "decision": "pass",
+      "note": "Passes only against its own (already-regressed) predecessor, curric-s3-no_draws. Evaluated directly against grounded curric-s2-defend (2026-07-22T11:40:07), curric-s4-mechanics also loses clearly: 24-57-19. Do not treat this stage's 'pass' as evidence curric-s4-mechanics is the strongest available model overall — see stage 2's note and stage_index 4 (aggression)."
     }
   ]
 }

training/eval_history.json

@@ -58,5 +58,35 @@
     "wins_b": 19,
     "draws": 37,
     "win_rate_a": 0.44
+  },
+  {
+    "timestamp": "2026-07-22T11:36:42+00:00",
+    "model_a": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s3-no_draws.json",
+    "model_b": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s2-defend.json",
+    "episodes": 100,
+    "wins_a": 26,
+    "wins_b": 60,
+    "draws": 14,
+    "win_rate_a": 0.26
+  },
+  {
+    "timestamp": "2026-07-22T11:38:57+00:00",
+    "model_a": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s4-mechanics.json",
+    "model_b": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s3-no_draws.json",
+    "episodes": 100,
+    "wins_a": 26,
+    "wins_b": 33,
+    "draws": 41,
+    "win_rate_a": 0.26
+  },
+  {
+    "timestamp": "2026-07-22T11:40:07+00:00",
+    "model_a": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s4-mechanics.json",
+    "model_b": "/Users/jcreek/Documents/repos/GitHub/CosmicClash/Game/bots/curric-s2-defend.json",
+    "episodes": 100,
+    "wins_a": 24,
+    "wins_b": 57,
+    "draws": 19,
+    "win_rate_a": 0.24
   }
 ]

training/train.py

@@ -84,6 +84,18 @@ def parse_args():
         default=None,
         help="Allow pitch/roll rotation (default true)",
     )
+    curriculum.add_argument(
+        "--velocity-to-ball-weight", type=float, default=None,
+        help="Overrides ShipAIController.velocity_to_ball_weight (dense reward for closing speed toward the ball)",
+    )
+    curriculum.add_argument(
+        "--ball-distance-penalty", type=float, default=None,
+        help="Overrides ShipAIController.ball_distance_penalty (dense per-tick cost scaled by distance to the ball)",
+    )
+    curriculum.add_argument(
+        "--ball-touch-reward", type=float, default=None,
+        help="Overrides ShipAIController.ball_touch_reward (event reward on ball contact, cooldown-gated)",
+    )
 
     return parser.parse_args()
 
@@ -101,6 +113,9 @@ def _curriculum_kwargs(args) -> dict:
         "ball_near_goal_chance": args.near_goal_chance,
         "ai_allow_vertical": args.allow_vertical,
         "ai_allow_pitch_roll": args.allow_pitch_roll,
+        "ai_velocity_to_ball_weight": args.velocity_to_ball_weight,
+        "ai_ball_distance_penalty": args.ball_distance_penalty,
+        "ai_ball_touch_reward": args.ball_touch_reward,
     }
     return {key: value for key, value in mapping.items() if value is not None}