docs: document the restored Crawler environment (card + NOTICE)

Adds Crawler back to the environment table, layout, per-env section, provenance and license lists, and records it in NOTICE as a release_23-derived build with its unmodified stock policy. Attribution follows the current release_23 wording, not the stale release_20 text the environment carried before removal.

NOTICE

@@ -11,9 +11,9 @@ Unity ML-Agents Toolkit
   https://github.com/Unity-Technologies/ml-agents
 
 Modifications by ccnets (stated per Apache-2.0 section 4b):
-  - The Unity builds under `3DBallHard/`, `PushBlock/`, `Pyramids/`, `Worm/`,
-    `Walker/`, `DungeonEscape/`, and `SoccerTwos/` were produced from customized
-    ML-Agents projects derived from `ml-agents-release_23`.
+  - The Unity builds under `Crawler/`, `3DBallHard/`, `PushBlock/`, `Pyramids/`,
+    `Worm/`, `Walker/`, `DungeonEscape/`, and `SoccerTwos/` were produced from
+    customized ML-Agents projects derived from `ml-agents-release_23`.
   - Each build's baked-in policy was removed so the build accepts actions from
     an externally supplied policy at run time.
   - `SoccerTwos.onnx` derives from the release-23 SoccerTwos stock policy. Its
@@ -26,14 +26,16 @@ Modifications by ccnets (stated per Apache-2.0 section 4b):
     parameters and the pre-existing outputs were not changed; the extra output
     lets a softmax temperature synthesize the calibrated `medium` / `simple`
     dataset tiers.
-  - The `3DBallHard/` and `PushBlock/` builds additionally carry Unity Barracuda
-    assemblies (`Unity.Barracuda*.dll`) and `Unity.ML-Agents.Extensions*.dll`
-    left over from an earlier generation of those projects. They are inert here:
+  - The `Crawler/`, `3DBallHard/`, and `PushBlock/` builds additionally carry
+    Unity Barracuda assemblies (`Unity.Barracuda*.dll`) and
+    `Unity.ML-Agents.Extensions*.dll` left over from an earlier generation of
+    those projects. They are inert here:
     the shipped `Unity.ML-Agents.dll` references `Unity.InferenceEngine` only.
   - No changes to the ML-Agents Python source are distributed in this repository.
 
 Stock policies from `ml-agents-release_23`, redistributed unchanged under
 Apache-2.0 (byte-identical to the upstream files):
+  - `Crawler.onnx`        — `Crawler/TFModels/Crawler.onnx`
   - `3DBallHard.onnx`     — `3DBall/TFModels/3DBallHard.onnx`
   - `PushBlock.onnx`      — `PushBlock/TFModels/PushBlock.onnx`
   - `Pyramids.onnx`       — `Pyramids/TFModels/Pyramids.onnx`

README.md

@@ -12,7 +12,7 @@ tags:
 
 Public **materials** for running Causal GPT-RL policies in Unity ML-Agents. Each
 environment is a **model-removed Unity build** — the engine binary with no
-baked-in policy; the policy is supplied at run time. All seven environments are
+baked-in policy; the policy is supplied at run time. All eight environments are
 paired with their **stock built-in policies**, and the four discrete-action ones
 additionally ship a logits-exposing variant under `tier_policies/`.
 
@@ -20,6 +20,7 @@ additionally ship a logits-exposing variant under `tier_policies/`.
 
 | Environment | Build | Stock policy | Agents | Observation | Action |
 |---|---|---|---:|---|---|
+| Crawler | `Crawler/` | `Crawler.onnx` | 10 | `158` (`126 + 32`) | `Box(20)` continuous |
 | 3DBallHard | `3DBallHard/` | `3DBallHard.onnx` | 12 | `45` (`27 + 18`) | `Box(2)` continuous |
 | PushBlock | `PushBlock/` | `PushBlock.onnx` | 32 | `210` (`105 + 105`) | `Discrete(7)` |
 | DungeonEscape | `DungeonEscape/` | `DungeonEscape.onnx` | 36 | `371` | `Discrete(7)` |
@@ -40,6 +41,14 @@ measurement recipe:
 ## Layout
 
 ```text
+Crawler/                       # release-23 model-removed Unity build
+  Crawler.exe
+  UnityPlayer.dll
+  UnityCrashHandler64.exe
+  Crawler_Data/
+  MonoBleedingEdge/
+Crawler.onnx                   # stock built-in policy (ml-agents-release_23)
+
 3DBallHard/                    # model-removed Unity build
   3DBallHard.exe
   UnityPlayer.dll
@@ -103,6 +112,16 @@ Each build is **model-removed**: no policy is baked in — supply one at run tim
 (the stock policy here, or the Causal GPT-RL policy from the model repo). All
 launch headless.
 
+## Crawler
+
+- Scene: **10 agents**, observation **158**-d (sensor channels `126 + 32`), action
+  `Box(20)` continuous, behavior `Crawler?team=0`. In the companion dataset the
+  observation is stored as `Tuple(Box(126), Box(32))`.
+- Built from the customized **ML-Agents release-23** project with the baked model
+  removed. `Crawler.onnx` is the unmodified release-23 stock policy used as the
+  collection driver; size `2,472,183` bytes, SHA-256
+  `df5dd19f28e89678f96b794e911564c21d0039160e88d99fe04f3939442ffdd7`.
+
 ## 3DBallHard
 
 - Scene: **12 agents**, observation **45**-d (sensor channels `27 + 18`), action
@@ -181,7 +200,7 @@ download before running.
 
 ## Provenance & scope
 
-- The builds were produced from **customized ML-Agents projects**. PushBlock, Pyramids, Worm, Walker, DungeonEscape, and SoccerTwos
+- The builds were produced from **customized ML-Agents projects**. Crawler, PushBlock, Pyramids, Worm, Walker, DungeonEscape, and SoccerTwos
   derive from `ml-agents-release_23`. The distributed stock policies
   match their respective build contracts. Other example scenes are not included.
 - **Not source-rebuildable** from stock ML-Agents: the project changes live in the
@@ -191,8 +210,8 @@ download before running.
 
 ## License
 
-The Unity builds and the stock policies (`PushBlock.onnx`, `Pyramids.onnx`, `Worm.onnx`,
-`Walker.onnx`, `3DBallHard.onnx`, `SoccerTwos.onnx`, `DungeonEscape.onnx`) are
+The Unity builds and the stock policies (`Crawler.onnx`, `PushBlock.onnx`, `Pyramids.onnx`,
+`Worm.onnx`, `Walker.onnx`, `3DBallHard.onnx`, `SoccerTwos.onnx`, `DungeonEscape.onnx`) are
 **Apache-2.0** (Unity ML-Agents), as are the `tier_policies/` exports derived from
 them. See `LICENSE` and
 `NOTICE`. The builds are modified derivatives — the modifications are described in