spec_version: "1.0"
rule:
  id: stale-edit-recovery
  version: "1.0.0"
  owner: agent-platform
  enabled: false
  mode: shadow

trigger:
  tool: file_edit
  structured_error_code: STALE_PRECONDITION
  required_context:
    - target_path
    - expected_pre_change_digest
    - intended_patch
  do_not_match_on:
    - Free-form model interpretation alone

safety:
  risk_class: reversible_local_write
  authorized_paths:
    - repo://current-worktree/**
  forbidden_actions:
    - Replace the entire file
    - Expand write scope
    - Delete content outside the intended patch
  max_attempts: 1
  max_files_changed: 1
  max_lines_changed: 100
  require_clean_or_isolated_worktree: true
  idempotency_key: "${trace_id}:${tool_call_id}:${rule.version}"

preconditions:
  - The original action was authorized.
  - The target is a regular file inside the authorized scope.
  - The intended change is still semantically valid after rereading.
  - A fresh digest differs from expected_pre_change_digest.
  - The new patch can be constructed without replacing the entire file.

remediation:
  steps:
    - Read the current target bytes.
    - Recompute the minimal patch against current content.
    - Re-run policy and scope checks.
    - Apply exactly one conditional edit.
  timeout_seconds: 30

verification:
  required:
    - The intended invariant holds.
    - The file parses or compiles where applicable.
    - Only the declared file and intended region changed.
    - The original tool error no longer occurs.
  evidence:
    - before_digest
    - after_digest
    - diff_uri
    - verification_command
    - verification_exit_status

failure:
  on_precondition_failure: escalate_without_mutation
  on_remediation_failure: escalate_without_second_retry
  on_verification_failure: restore_pre_change_bytes_and_escalate
  on_unknown_effect: reconcile_before_any_retry

circuit_breaker:
  open_when:
    - 2 verification failures in 10 minutes
    - 1 rollback failure
    - 3 matching failures on the same target in one run
  cooldown_minutes: 60
  reset_requires: owner_review

issue_emission:
  emit_when:
    - circuit breaker opens
    - the same fingerprint recurs after a verified recovery
    - rollback fails
  include:
    - rule_id
    - rule_version
    - failure_fingerprint
    - trace_id
    - attempts
    - evidence_uris