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/persistence/models/automation.py

@@ -1,4 +1,4 @@
-"""``Automation`` table — the editable, versioned automation definition."""
+"""``automations`` table — editable, versioned automation definition."""
 
 from __future__ import annotations
 
@@ -21,15 +21,6 @@ from ..enums.automation_status import AutomationStatus
 
 
 class Automation(BaseModel, TimestampMixin):
-    """The editable, versioned spec a user authors.
-
-    The ``definition`` JSON is what the user (or the NL generator) writes
-    and edits. Each save bumps ``version`` by one; the previous JSON is
-    not kept in this row — version history is reconstructed from the
-    ``definition_snapshot`` column on every ``AutomationRun`` that fired
-    against a given version.
-    """
-
     __tablename__ = "automations"
 
     search_space_id = Column(
@@ -59,12 +50,7 @@ class Automation(BaseModel, TimestampMixin):
 
     definition = Column(JSONB, nullable=False)
 
-    version = Column(
-        Integer,
-        nullable=False,
-        default=1,
-        server_default="1",
-    )
+    version = Column(Integer, nullable=False, default=1, server_default="1")
 
     updated_at = Column(
         TIMESTAMP(timezone=True),