M3.1: action classes and the fast path

Every execution tool call, the driver's and a helper's, gets a verdict
from code before it runs (P3, P4, D6).

- nisse_core.actions, nisse-core's first code: Action and Verdict, and
  reading shell commands statically, segment by segment (cd, wrappers,
  sh -c). What can't be read that way is unknown; a line is as bad as
  its worst command.
- nisse_dev.loop.actions, the rule table: reading, checks and tests are
  harmless; workspace edits, local git and installs on the build VM are
  contained; pushing, other hosts, uploads, publishing, the forge's own
  tools, deleting outside the workspace and wrecking the VM are
  dangerous; changing branches by hand is refused (the harness owns
  branches) with a pointer to the milestone tools.
- A dangerous call isn't run. The item waits on the operator with a
  question rendered from the action, and `allow` lets exactly that
  action run once. A helper can't ask, so it is refused and told to
  hand back. Unknown actions run, logged, until the classifier (M3.2).
- Every verdict is an action_verdict event, which no model sees, and an
  oplog line; `details` shows the counts and every action not simply
  run.
- The property walk gains dangerous_only_when_allowed (checked against
  a mutant that doesn't use the allow up); the slice e2e checks every
  call was judged and none needed an allow.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

nisse-dev/src/nisse_dev/views.py

@@ -20,6 +20,7 @@ ranges still line up with the log. Everything not the viewer's own becomes a
 from dataclasses import replace
 
 from nisse_dev.canonical import (
+    ActionVerdict,
     AssistantText,
     DelegationCompleted,
     DelegationStarted,
@@ -86,6 +87,8 @@ def _narration(call: ToolCall, result: ToolResult | None) -> str:
 
 def project(events: list[StoredEvent], viewer: str) -> list[StoredEvent]:
     """The events as ``viewer`` should be shown them, in log order."""
+    # Verdicts are records about calls, never part of any role's context.
+    events = [e for e in events if not isinstance(e.event, ActionVerdict)]
     shown = _SHOWN.get(viewer)
     if shown is None:
         # A role with no view defined (the expert is stateless, the