feat(harness): implement Plan-20 transparent agentic client bridge

Wave 0 + Wave 1 core of the transparent agentic-client integration: a
developer types prompts normally in Claude Code / Codex while every
certified turn still carries a full H1->H7 trace and an H6 record.

- agentic_bridge.py: stdlib-only lifecycle state machine (begin/pre-tool/
  post-tool/telemetry/finalize/abort + report/doctor). Single-model
  invariant (never calls a model), fail-closed at the side-effect point,
  admission TTL + canonical-project/session binding, atomic state under
  .specify/state/agentic-sessions/, secret redaction, null-not-zero H6.
- agentic-lifecycle.schema.json: client-agnostic JSON contract.
- adapters/claude-code + adapters/codex: thin hook renderers + config
  templates that call the core bridge.
- phase-agentic-bridge-tests.sh: C1-C12 acceptance + threat suite (30/30).
- devkit templates/{claude,codex} + windows/install-agentic.ps1
  (install/doctor/uninstall with manifest, path-safe).
- docs/casan Windows + security/bypass guides; plan status -> IMPLEMENTED.
- harden generate-agentops-dashboard.py aggregation against null H6 costs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packages/casan-harness/adapters/codex/config.template.toml

@@ -0,0 +1,18 @@
+# CASAN Plan-20 Codex config fragment (.codex/config.toml).
+# Merge these keys into the target repo's .codex/config.toml. This enables the
+# project hooks in hooks.template.json after Codex trust review.
+#
+# For ENTERPRISE enforcement, the managed policy path pins hooks so a member
+# cannot disable them (Spike-20 §4.2, Plan-20 Wave 3.3). In that deployment set
+# CASAN_AGENTIC_INTEGRATION_MODE=managed_hook via managed environment/MDM, not
+# in this committed file.
+
+[hooks]
+enabled = true
+# project-local hooks load only after the user accepts the trust prompt.
+project_hooks = true
+
+[casan]
+# Bridge feature flags — safe defaults (observe first, then enforce per Plan-20 §9).
+enforcement_mode = "observe"   # observe | enforce
+integration_mode = "project_hook"