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/plan_step.py

@@ -1,4 +1,4 @@
-"""``PlanStep`` — one entry in the envelope's ``plan`` array."""
+"""``PlanStep`` — one step in the sequential plan."""
 
 from __future__ import annotations
 
@@ -8,79 +8,21 @@ from pydantic import BaseModel, ConfigDict, Field
 
 
 class PlanStep(BaseModel):
-    """One step in an automation's sequential plan.
-
-    Steps run in array order, no parallelism, no DAGs, no loops. The
-    ``when`` Jinja expression provides conditional skip; branching is
-    achieved by ``when`` clauses on multiple steps. For looping or
-    parallel work, the user routes through ``agent_task`` and lets the
-    agent reason about it.
-
-    ``config`` is dispatched against the action registry at
-    validation time — its shape is determined by
-    ``ActionDefinition.config_schema`` for the ``action`` value.
-
-    ``output_as`` binds the step's typed output into the template
-    namespace for later steps, e.g. ``output_as: 'summary'`` then
-    ``{{ summary.bullets }}`` in a downstream step's config.
-    """
-
     model_config = ConfigDict(extra="forbid")
 
-    step_id: str = Field(
-        ...,
-        description=(
-            "Unique-within-plan identifier. Used in run logs and as "
-            "the default for ``output_as`` when not provided."
-        ),
-        min_length=1,
-    )
-    action: str = Field(
-        ...,
-        description=(
-            "Action-type discriminator (e.g., ``agent_task``). "
-            "Resolved against the action registry."
-        ),
-        min_length=1,
-    )
+    step_id: str = Field(..., min_length=1, description="Unique within the plan.")
+    action: str = Field(..., min_length=1, description="Action type; resolved via registry.")
     when: str | None = Field(
         default=None,
-        description=(
-            "Optional Jinja expression evaluated against the run "
-            "context. Step is skipped when the expression is "
-            "falsy."
-        ),
+        description="Optional Jinja expression; step is skipped when falsy.",
     )
     config: dict[str, Any] = Field(
         default_factory=dict,
-        description=(
-            "Action-type-specific config. Validated against the "
-            "registered ``ActionDefinition.config_schema`` for "
-            "``action`` at definition-save time. Jinja templates "
-            "inside config are rendered at step-execute time."
-        ),
+        description="Action-type-specific config; Jinja-rendered at execute time.",
     )
     output_as: str | None = Field(
         default=None,
-        description=(
-            "Name to bind the step output under for downstream "
-            "steps. Defaults to ``step_id`` when omitted."
-        ),
-    )
-    max_retries: int | None = Field(
-        default=None,
-        ge=0,
-        description=(
-            "Per-step override of the automation-level ``max_retries``. "
-            "Omitted means inherit from execution block."
-        ),
-    )
-    timeout_seconds: int | None = Field(
-        default=None,
-        gt=0,
-        description=(
-            "Per-step override of the automation-level "
-            "``timeout_seconds``. Omitted means inherit from "
-            "execution block."
-        ),
+        description="Bind step output under this name. Defaults to step_id.",
     )
+    max_retries: int | None = Field(default=None, ge=0)
+    timeout_seconds: int | None = Field(default=None, gt=0)