tera-crow-nav: the first spatial taskset, and the hold sweep that sized its budget

The bridge becomes a runnable taskset. The crux is that these are continuous
control environments and the agent emits text: the model issues a control
decision that is held for N steps, and the hold length is measured rather than
guessed. At one decision every 32 steps the scripted baseline returns -2.807 and
reaches the waypoint 0% of the time, against 5.484 and 100% at every frame.

Open loop — one decision for the whole flight — returns -3.764 against an
inaction floor of -4.161. A bird that sets a course and leaves does no better
than one that does nothing, which is why crow-nav carries the strongest rule-4
claim of the five spatial environments. The budget bites from both ends: 8 turns
reach the goal 44% of the time, 12 reach 88%, 14 reach 100%.

32 episodes against Qwen3.8-27B: mean 0.4603, no malformed replies in 412, every
episode replaying to an identical checksum, and 16 of 32 spending all 16 turns.
The gate fires 43.75% of the time and separates the four scenarios cleanly —
whatever is wrong with the four dead data-environment gates, it is not that
binary gates cannot discriminate.

The oracle comes from the worker's own op. Nothing recomputes in Python a number
that came out of TypeScript, least of all the reward denominator.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

environments/tera_spatial/tera_crow_nav/__init__.py

@@ -0,0 +1,18 @@
+"""tera-crow-nav — the first Tera spatial taskset, over the NDJSON bridge.
+
+The taskset id resolves to this module name, so both plugin classes are exported
+from here: the `Taskset` the run loads its tasks from, and the `Env` that programs
+the flight loop host-side. `TeraSpatialEnv` lives in `tera_spatial` because the
+loop is the same for every spatial environment; what makes this one crow-nav is
+`CrowNavTaskset`.
+"""
+
+from tera_crow_nav.taskset import CrowNavConfig, CrowNavTaskset
+from tera_spatial.spatial import TeraSpatialEnv, TeraSpatialEnvConfig
+
+__all__ = [
+    "CrowNavConfig",
+    "CrowNavTaskset",
+    "TeraSpatialEnv",
+    "TeraSpatialEnvConfig",
+]