diff --git a/docs/adr/0001-truth-surfaces-b11-delta-appendix-a-reuse-map.md b/docs/adr/0001-truth-surfaces-b11-delta-appendix-a-reuse-map.md
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+# ADR-0001 Appendix A — Reuse map + schema plan (B¹¹ / Δ / incidents)
+
+**Date:** 2026-04-14  
+**Status:** Proposed (appendix to ADR-0001)
+
+---
+
+## Purpose
+
+ADR-0001 establishes the decision to add TruthSurface (B¹¹) and DeltaSurface (Δ) and to standardize incident semantics. This appendix makes the decision *actionable* by:
+
+1) specifying a reuse-first mapping onto existing contracts already present in this repo, and  
+2) enumerating the minimal net-new schema files + examples required for v0 portability.
+
+---
+
+## Reuse-first mapping
+
+| Capability we need | Reuse (existing contracts / patterns) | Net-new (v0) |
+|---|---|---|
+| Signed “truth summary” per plane | Reuse **URN + `type` discriminator + `specVersion`** conventions (e.g., `TelemetryEvent`). Reuse existing evidence references (PolicyDecision/CapabilityToken/RunRecord/ProvenanceRecord) as *refs*, not embedded duplicates. | `schemas/TruthSurface.json` + `examples/truth-surface.sample.json` |
+| Typed diff between two truth summaries | Reuse existing “risk + evidence + human approval” posture expressed in `policies/skills/default-policy-pack.rego` as the canonical gate style; DeltaSurface records the gate results, it does not *re-decide* policy. | `schemas/DeltaSurface.json` + `examples/delta-surface.sample.json` |
+| Incident semantics (Freeze/Fork/Kill) | Reuse control-plane event structure conventions: `event_id`, `event_name`, `occurred_at`, `actor`, `run`, `refs`, `payload` as in the existing skill execution lifecycle schema and samples. | `schemas/control-plane/incident-events.schema.json` + `examples/control-plane/incident.freeze.sample.json` |
+| Frontier / PBAC egress authorization | Reuse `CapabilityToken` as the short-lived signed grant primitive. Treat frontier/network constraints as a profile extension (additive) aligned to the existing governance lifecycle (decision → token). | v0: represent frontier intent + result refs in TruthSurface/DeltaSurface. v1: add an additive `frontier` block to `CapabilityToken.scope` (separate ADR if needed). |
+
+---
+
+## Schema plan (v0)
+
+New schema files added in this PR branch:
+
+1) `schemas/TruthSurface.json`
+2) `schemas/DeltaSurface.json`
+3) `schemas/control-plane/incident-events.schema.json`
+
+New example payloads added in this PR branch:
+
+1) `examples/truth-surface.sample.json`
+2) `examples/delta-surface.sample.json`
+3) `examples/control-plane/incident.freeze.sample.json`
+
+---
+
+## Non-goals for v0
+
+- No OpenAPI/AsyncAPI surface changes yet (schemas stabilize first).
+- No in-place `CapabilityToken` extension yet (we keep the profile extension as a documented plan until agreed).
+- No enforcement logic (belongs in the substrate repo).
+
+---
+
+## Follow-on steps (expected)
+
+1) Add OpenAPI/AsyncAPI patch entries for TruthSurface/DeltaSurface publishing endpoints + event channels.
+2) Add conformance fixtures in workstation-contracts (schema validation + golden examples).
+3) Implement substrate emitters/enforcers in SociOS-Linux/SourceOS (services + nftables + incident executor).
+
diff --git a/docs/adr/0001-truth-surfaces-b11-delta.md b/docs/adr/0001-truth-surfaces-b11-delta.md
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+# ADR-0001 — Truth Surfaces (B¹¹) + Δ-Surfaces + Incident Semantics
+
+**Date:** 2026-04-14  
+**Status:** Proposed
+
+---
+
+## Context
+
+We need a *portable, machine-verifiable* way to represent “what is true right now” about:
+
+- the immutable substrate (host integrity and policy posture),
+- the controlled user space (governed meaning and intent),
+- the agent space (bounded execution and decisions), and
+- the witness/replication posture (what was attested externally).
+
+In practice, the system already carries many of these primitives:
+
+- The **two-plane contract model** (metadata plane + agent plane) and additive patch strategy (`openapi*.yaml`, `asyncapi*.yaml`).
+- A **short-lived signed grant** primitive (`schemas/CapabilityToken.json`) derived from policy decisions.
+- A **control-plane event lifecycle** style (e.g., `schemas/control-plane/skill-execution-events.schema.json`) and a default skill policy pack (`policies/skills/default-policy-pack.rego`).
+- A concrete *mesh skill* example that already encodes deterministic plans, evidence requirements, and Cairn refs (`examples/control-plane/mesh-skill.checkout-validate.yaml`).
+
+What is missing is a canonical “truth object” that can be:
+
+1) generated deterministically,  
+2) signed and Merkle-addressed,  
+3) compared across time and planes (Δ), and  
+4) gated/promoted with explicit thresholds and evidence requirements.
+
+We also need incident semantics that are explicit and replayable (Freeze → Fork → Kill) rather than implicit operational folklore.
+
+## Decision
+
+### 1) Add two new contract types (schema family) to `sourceos-spec`
+
+We introduce **TruthSurface** (B¹¹) and **DeltaSurface** (Δ) as first-class contract objects, published alongside the existing schema families.
+
+- **TruthSurface (B¹¹)**: a signed, Merkle-addressed summary for a given plane (`sealed/system`, `controlled/user`, `open/agent`, `witness/twin`).
+- **DeltaSurface (Δ)**: a signed diff between two TruthSurfaces with:
+  - semantic drift metrics,
+  - runtime drift metrics,
+  - governance deltas,
+  - a promotion recommendation + gate results.
+
+These new types must compose cleanly with existing primitives (TelemetryEvent, ExecutionDecision, PolicyDecision/CapabilityToken, ProvenanceRecord) rather than replacing them.
+
+### 2) Represent “PBAC tickets” as a CapabilityToken profile, not a new token class
+
+Off-box / frontier egress authorization is expressed as a **CapabilityToken** profile extension:
+
+- add network scope constraints (e.g., `frontier_hops`, `targets`, `egress_class`) as structured fields,
+- keep the existing governance flow (evaluate → decision → issue token),
+- ensure tokens remain short-lived and auditable.
+
+This prevents parallel token taxonomies.
+
+### 3) Standardize incident semantics as contract-level events
+
+We define incident semantics as a small set of event types aligned with the existing control-plane event lifecycle style:
+
+- `incident.freeze`
+- `incident.fork`
+- `incident.kill`
+
+Each event MUST carry:
+- actor context (human/agent/service),
+- run/trace linkage (when applicable),
+- refs to evidence bundles and pre/post Cairn anchors,
+- status progression compatible with existing control-plane conventions.
+
+### 4) Promotion gates are contract-level, evidence-first
+
+Promotion of a surface (or a claim derived from it) requires explicit gate checks:
+
+- evidence bundle completeness (required evidence list satisfied),
+- risk threshold checks,
+- approval rules (e.g., human approval required for certain classes),
+- semantic coherence thresholds,
+- runtime integrity thresholds.
+
+We explicitly reuse the posture already present in `policies/skills/default-policy-pack.rego` (risk gating, human approval requirement, evidence requirement checking) as the canonical style baseline.
+
+### 5) Keep enforcement out of this repository
+
+`sourceos-spec` defines **what** a surface/token/event is.
+Enforcement remains the responsibility of the substrate and runtime implementations (e.g., `SociOS-Linux/SourceOS`).
+
+## Alternatives considered
+
+| Alternative | Reason not chosen |
+|-------------|------------------|
+| Put truth surfaces directly in the substrate repo only | Breaks the “canonical contract registry” role of this repo; makes portability and interoperability harder. |
+| Create a new standalone “truth-surface spec” repo | Fragments the spec; duplicates identity/versioning discipline; increases coordination overhead. |
+| Use only existing TelemetryEvent/ExecutionDecision structures | Those are necessary components but not sufficient as a signed, Merkle-addressed *summary surface* with promotion gating and Δ comparison. |
+
+## Consequences
+
+Positive:
+- A single canonical contract for truth, drift, and gating across planes.
+- Enables conformance fixtures and independent validators (e.g., workstation lanes).
+- Allows implementations to evolve while remaining interoperable (schemas, OpenAPI, AsyncAPI, JSON-LD).
+
+Negative:
+- Adds schema surface area that must be versioned and maintained.
+- Requires a clear reuse map to prevent duplication with existing agent-plane primitives.
+
+## References
+
+- `ARCHITECTURE.md` — two-plane model and patch-file composition strategy.
+- `schemas/CapabilityToken.json` — existing short-lived signed grant primitive.
+- `schemas/control-plane/skill-execution-events.schema.json` — lifecycle event conventions.
+- `policies/skills/default-policy-pack.rego` — baseline risk/evidence/approval gating style.
+- `examples/control-plane/mesh-skill.checkout-validate.yaml` — deterministic plan + evidence requirements + Cairn refs.
+- `examples/control-plane/skill.evidence.attached.sample.json` — concrete event sample for evidence attachment.
diff --git a/schemas/DeltaSurface.json b/schemas/DeltaSurface.json
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+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://schemas.srcos.ai/v2/DeltaSurface.json",
+  "title": "DeltaSurface",
+  "description": "A signed diff between two TruthSurfaces. Records drift metrics + gate results + recommendation. This is an interoperability artifact and should reference existing evidence/provenance objects, not duplicate them.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["id", "type", "specVersion", "fromRef", "toRef", "createdAt", "merkleRoot", "signature", "gate"],
+  "properties": {
+    "id": {
+      "type": "string",
+      "pattern": "^urn:srcos:delta-surface:",
+      "description": "Stable URN identifier. Pattern: urn:srcos:delta-surface:<local-id>"
+    },
+    "type": {
+      "const": "DeltaSurface",
+      "description": "Discriminator constant — always \"DeltaSurface\"."
+    },
+    "specVersion": {
+      "type": "string",
+      "description": "Spec version of this document (e.g., \"2.0.0\")."
+    },
+    "createdAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "ISO 8601 timestamp when this delta surface was produced."
+    },
+    "merkleRoot": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Merkle root over referenced artifacts (format is producer-defined; commonly sha256:<hex>)."
+    },
+    "signer": {
+      "type": "string",
+      "description": "Logical signer identity (key or service name)."
+    },
+    "signature": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Cryptographic signature over the canonicalized delta payload."
+    },
+
+    "fromRef": {
+      "type": "string",
+      "pattern": "^urn:srcos:truth-surface:",
+      "description": "URN of the prior TruthSurface."
+    },
+    "toRef": {
+      "type": "string",
+      "pattern": "^urn:srcos:truth-surface:",
+      "description": "URN of the new TruthSurface."
+    },
+
+    "metrics": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Optional drift metrics. Keep metrics stable and documented to avoid metric sprawl.",
+      "properties": {
+        "semantic": {
+          "type": "object",
+          "additionalProperties": true,
+          "description": "Semantic drift summary (topic/anchor/glossary drift)."
+        },
+        "runtime": {
+          "type": "object",
+          "additionalProperties": true,
+          "description": "Runtime drift summary (process/thread/namespace posture changes)."
+        },
+        "governance": {
+          "type": "object",
+          "additionalProperties": true,
+          "description": "Governance drift summary (approvals, obligations, policy pack changes)."
+        }
+      }
+    },
+
+    "gate": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Gate evaluation result block (reuse the posture expressed in the default policy pack).",
+      "required": ["status"],
+      "properties": {
+        "status": {
+          "type": "string",
+          "enum": ["permit", "deny", "needs_more_evidence"],
+          "description": "Overall gate outcome."
+        },
+        "riskScore": { "type": "integer", "minimum": 0 },
+        "riskThreshold": { "type": "integer", "minimum": 0 },
+        "humanApprovalRequired": { "type": "boolean" },
+        "humanApproved": { "type": "boolean" },
+        "evidenceRequired": { "type": "array", "items": { "type": "string" } },
+        "evidencePresent": { "type": "array", "items": { "type": "string" } },
+        "evidenceMissing": { "type": "array", "items": { "type": "string" } },
+        "reasons": { "type": "array", "items": { "type": "string" } }
+      }
+    },
+
+    "refs": {
+      "type": "object",
+      "additionalProperties": true,
+      "description": "Pointers to evidence bundles, policy decisions, and Cairn anchors relevant to this delta."
+    }
+  }
+}
diff --git a/schemas/TruthSurface.json b/schemas/TruthSurface.json
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+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://schemas.srcos.ai/v2/TruthSurface.json",
+  "title": "TruthSurface",
+  "description": "A signed, Merkle-addressed truth summary emitted by a plane (system/user/agent/witness). This is an interoperability artifact: it references existing governance/provenance objects, it does not replace them.",
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["id", "type", "specVersion", "plane", "createdAt", "merkleRoot", "signature"],
+  "properties": {
+    "id": {
+      "type": "string",
+      "pattern": "^urn:srcos:truth-surface:",
+      "description": "Stable URN identifier. Pattern: urn:srcos:truth-surface:<local-id>"
+    },
+    "type": {
+      "const": "TruthSurface",
+      "description": "Discriminator constant — always \"TruthSurface\"."
+    },
+    "specVersion": {
+      "type": "string",
+      "description": "Spec version of this document (e.g., \"2.0.0\")."
+    },
+    "plane": {
+      "type": "string",
+      "enum": ["system.sealed", "user.controlled", "agent.open", "witness.twin"],
+      "description": "Which plane emitted this surface."
+    },
+    "createdAt": {
+      "type": "string",
+      "format": "date-time",
+      "description": "ISO 8601 timestamp when this surface was produced."
+    },
+    "merkleRoot": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Merkle root over referenced artifacts (format is producer-defined; commonly sha256:<hex>)."
+    },
+    "signer": {
+      "type": "string",
+      "description": "Logical signer identity (key or service name)."
+    },
+    "signature": {
+      "type": "string",
+      "minLength": 1,
+      "description": "Cryptographic signature over the canonicalized surface payload."
+    },
+
+    "refs": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Pointers to existing governance/provenance objects and evidence bundles.",
+      "properties": {
+        "policyDecisionRefs": {
+          "type": "array",
+          "items": { "type": "string", "pattern": "^urn:srcos:decision:" }
+        },
+        "capabilityTokenIds": {
+          "type": "array",
+          "items": { "type": "string" }
+        },
+        "runRecordRefs": {
+          "type": "array",
+          "items": { "type": "string", "pattern": "^urn:srcos:run:" }
+        },
+        "provenanceRefs": {
+          "type": "array",
+          "items": { "type": "string", "pattern": "^urn:srcos:prov:" }
+        },
+        "telemetryRefs": {
+          "type": "array",
+          "items": { "type": "string", "pattern": "^urn:srcos:telemetry:" }
+        },
+        "evidenceBundleRefs": {
+          "type": "array",
+          "items": { "type": "string" }
+        },
+        "cairnBeforeRef": { "type": "string" },
+        "cairnAfterRef": { "type": "string" }
+      }
+    },
+
+    "evidence": {
+      "type": "object",
+      "additionalProperties": false,
+      "description": "Evidence completeness panel. Producers should keep this summary aligned with the policy pack expectations.",
+      "properties": {
+        "required": { "type": "array", "items": { "type": "string" } },
+        "present": { "type": "array", "items": { "type": "string" } },
+        "missing": { "type": "array", "items": { "type": "string" } }
+      }
+    },
+
+    "semantics": {
+      "type": "object",
+      "additionalProperties": true,
+      "description": "Governed meaning summary: anchors/topics/glossary bindings. Shape may evolve; keep stable keys where possible."
+    },
+
+    "runtime": {
+      "type": "object",
+      "additionalProperties": true,
+      "description": "Runtime truth summary (process/thread/namespace/capability posture). Shape may evolve; keep stable keys where possible."
+    },
+
+    "governance": {
+      "type": "object",
+      "additionalProperties": true,
+      "description": "Governance posture summary (approvals, risk score, obligations satisfied, policy pack digest)."
+    }
+  }
+}