chore(automation): trim docstrings to intent only

Cut the docstrings and Field(description=...) text across the entire
automations/ tree down to single-line intent statements, matching the
multi_agent_chat conciseness style:

- Module docstrings: one line stating what the file is.
- Class docstrings: deleted when the class name + module docstring
  already cover intent; kept only where they add a constraint or
  rationale not visible in the signature.
- Pydantic Field descriptions: short noun phrases / clauses, not
  full sentences. Reasoning that belonged in the design plan moved
  out of the code.
- Enum values: per-value docstrings replaced with terse inline
  comments where the meaning isn't obvious from the name.

Behaviour is unchanged. The same 33 files, same public surface, same
imports — verified by re-running the 10-point registry smoke test and
the 8-point schema round-trip / constraint suite from commits 9 and
10.

LOC: 1180 → 691 (-42%).

surfsense_backend/app/automations/schemas/definition/trigger_spec.py

@@ -1,4 +1,4 @@
-"""``TriggerSpec`` — one entry in the envelope's ``triggers`` array."""
+"""``TriggerSpec`` — one entry in the definition's ``triggers[]`` array."""
 
 from __future__ import annotations
 
@@ -8,33 +8,10 @@ from pydantic import BaseModel, ConfigDict, Field
 
 
 class TriggerSpec(BaseModel):
-    """One trigger attached to an automation, as it appears in the definition.
-
-    The envelope keeps ``config`` as an untyped JSON object on purpose
-    — the per-type config schemas live in
-    ``app.automations.schemas.triggers`` and are dispatched at
-    validation time by looking up ``type`` in the trigger registry.
-
-    This mirrors the design's "definitions are pure data" principle:
-    the envelope describes shape, the registry resolves names to
-    behaviour.
-    """
-
     model_config = ConfigDict(extra="forbid")
 
-    type: str = Field(
-        ...,
-        description=(
-            "Trigger-type discriminator (e.g., ``schedule``, ``manual``). "
-            "Resolved against the trigger registry."
-        ),
-        min_length=1,
-    )
+    type: str = Field(..., min_length=1, description="Trigger type; resolved via registry.")
     config: dict[str, Any] = Field(
         default_factory=dict,
-        description=(
-            "Trigger-type-specific config. Validated against the "
-            "registered ``TriggerDefinition.config_schema`` for "
-            "``type`` at definition-save time."
-        ),
+        description="Type-specific config; validated against the trigger's schema.",
     )