cog-ha-matter (ADR-116 P8): app-registry entry stub + release checklist

Two closing P8 deliverables that complete the local-side publishing
scaffolding. The remaining work is all credential-bearing user
action.

1. `cog/app-registry-entry.json` — the exact JSON payload to paste
   into cognitum-one's `app-registry.json`. Schema discovered by
   fetching the live registry (105 cogs, 11 categories) and
   matching the existing `ruview-densepose` entry verbatim. Keys:

     id, name, category, version, size_kb, difficulty, description,
     featured, config[], sha256, binary_size

   cog-ha-matter slots in under `category: "building"` (smart home
   / building automation — the natural HA / Matter category, vs
   `network` which is more about transport bridges).

   7 config[] entries mirror our CLI surface:
     sensing_url, mqtt_host, mqtt_port, privacy_mode,
     mdns_hostname, mdns_ipv4, no_mdns

   Two post-build fields left as `<FILL_IN_...>` markers:
     sha256       (paste from the workflow artifact's .sha256)
     binary_size  (wc -c < the binary)

   Schema validated: all 10 required keys present, parses as JSON.

2. `cog/RELEASE-CHECKLIST.md` — one-page mechanical playbook with
   four explicit "🔑 USER ACTION" gates. Each gate names exactly
   what the user (or org admin) has to do that the pipeline cannot:

     a) provision GCP_CREDENTIALS + HAS_GCP_CREDENTIALS org var
     b) provision COGNITUM_OWNER_SIGNING_KEY GH secret
     c) gcloud auth login (only if uploading locally)
     d) PR app-registry.json into cognitum-one

   Plus pre-release test gate, tag-push command, post-release
   verification curl, and a rollback procedure using GCS object
   versioning (per ADR-100 §"GCS misconfiguration risks").

Stop-condition check (cron's predicate: "ALL local-side publishing
scaffolding is complete and the only remaining work requires user
action"):

  ✅ cog/manifest.template.json
  ✅ cog/Makefile (build / sign / upload / verify / clean)
  ✅ cog/README.md
  ✅ cog/app-registry-entry.json (this commit)
  ✅ cog/RELEASE-CHECKLIST.md (this commit)
  ✅ .github/workflows/cog-ha-matter-release.yml (3 jobs, gated)
  ✅ dist/ handling (gitignored, created by make)

  🔑 4 user-action gates explicitly enumerated in the checklist

The cron should STOP after this iter — the local-side scaffolding
is complete and the remaining work is the four named credential
gates that the pipeline cannot self-serve.

Co-Authored-By: claude-flow <ruv@ruv.net>

.github/workflows/cog-ha-matter-release.yml

@@ -0,0 +1,200 @@
+name: Cog HA-Matter Release
+
+# ADR-116 P8 — Build + sign + bundle the cog-ha-matter cog on a
+# version tag. Upload to gs://cognitum-apps/ runs only when the
+# GCP_CREDENTIALS + COGNITUM_OWNER_SIGNING_KEY secrets are set, so
+# this workflow is safe to merge before the production credentials
+# land — it'll bundle release artifacts to the workflow run page
+# either way.
+
+on:
+  push:
+    tags:
+      - 'cog-ha-matter-v*'
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: 'Build + sign + bundle but skip GCS upload'
+        required: false
+        default: 'true'
+
+env:
+  CARGO_TERM_COLOR: always
+  CRATE: cog-ha-matter
+
+jobs:
+  build-x86_64:
+    name: Build x86_64
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: x86_64-unknown-linux-gnu
+
+      - name: Cache cargo registry
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            v2/target
+          key: cog-ha-matter-x86_64-${{ hashFiles('v2/Cargo.lock') }}
+
+      - name: Build release binary
+        working-directory: v2/crates/cog-ha-matter/cog
+        run: make build-x86_64
+
+      - name: Compute SHA-256
+        working-directory: v2/crates/cog-ha-matter/cog
+        run: make sign-x86_64
+
+      - name: Sign with Ed25519 (gated)
+        if: ${{ env.SIGNING_KEY != '' }}
+        env:
+          SIGNING_KEY: ${{ secrets.COGNITUM_OWNER_SIGNING_KEY }}
+        working-directory: v2/crates/cog-ha-matter/cog
+        run: |
+          printf '%s' "$SIGNING_KEY" \
+            | openssl pkeyutl -sign -inkey /dev/stdin -rawin \
+                -in dist/cog-ha-matter-x86_64.sha256 \
+            | base64 -w0 > dist/cog-ha-matter-x86_64.sig
+          echo "Signed cog-ha-matter-x86_64 ($(wc -c < dist/cog-ha-matter-x86_64.sig) bytes)"
+
+      - name: Upload workflow artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: cog-ha-matter-x86_64
+          path: |
+            v2/crates/cog-ha-matter/cog/dist/cog-ha-matter-x86_64
+            v2/crates/cog-ha-matter/cog/dist/cog-ha-matter-x86_64.sha256
+            v2/crates/cog-ha-matter/cog/dist/cog-ha-matter-x86_64.sig
+          if-no-files-found: warn
+
+  build-arm:
+    name: Build aarch64 (arm)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          targets: aarch64-unknown-linux-gnu
+
+      - name: Install cross-compiler
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gcc-aarch64-linux-gnu
+
+      - name: Cache cargo registry
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            v2/target
+          key: cog-ha-matter-arm-${{ hashFiles('v2/Cargo.lock') }}
+
+      - name: Build release binary
+        working-directory: v2
+        env:
+          CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
+        run: |
+          cargo build -p cog-ha-matter --release --target aarch64-unknown-linux-gnu
+          mkdir -p crates/cog-ha-matter/cog/dist
+          cp target/aarch64-unknown-linux-gnu/release/cog-ha-matter \
+             crates/cog-ha-matter/cog/dist/cog-ha-matter-arm
+          # ^ matches Makefile's `dist/$(CRATE)-arm` so `make sign-arm` finds it
+
+      - name: Compute SHA-256
+        working-directory: v2/crates/cog-ha-matter/cog
+        run: make sign-arm
+
+      - name: Sign with Ed25519 (gated)
+        if: ${{ env.SIGNING_KEY != '' }}
+        env:
+          SIGNING_KEY: ${{ secrets.COGNITUM_OWNER_SIGNING_KEY }}
+        working-directory: v2/crates/cog-ha-matter/cog
+        run: |
+          printf '%s' "$SIGNING_KEY" \
+            | openssl pkeyutl -sign -inkey /dev/stdin -rawin \
+                -in dist/cog-ha-matter-arm.sha256 \
+            | base64 -w0 > dist/cog-ha-matter-arm.sig
+          echo "Signed cog-ha-matter-arm ($(wc -c < dist/cog-ha-matter-arm.sig) bytes)"
+
+      - name: Upload workflow artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: cog-ha-matter-arm
+          path: |
+            v2/crates/cog-ha-matter/cog/dist/cog-ha-matter-arm
+            v2/crates/cog-ha-matter/cog/dist/cog-ha-matter-arm.sha256
+            v2/crates/cog-ha-matter/cog/dist/cog-ha-matter-arm.sig
+          if-no-files-found: warn
+
+  publish-gcs:
+    name: Upload to GCS (gated)
+    needs: [build-x86_64, build-arm]
+    runs-on: ubuntu-latest
+    # Skip on dry-run dispatch; skip on tags when GCP_CREDENTIALS unset.
+    if: >
+      github.event_name == 'push' &&
+      vars.HAS_GCP_CREDENTIALS == 'true'
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download x86_64 artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: cog-ha-matter-x86_64
+          path: dist/
+
+      - name: Download arm artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: cog-ha-matter-arm
+          path: dist/
+
+      - name: Auth to GCP
+        uses: google-github-actions/auth@v2
+        with:
+          credentials_json: ${{ secrets.GCP_CREDENTIALS }}
+
+      - name: Set up gcloud
+        uses: google-github-actions/setup-gcloud@v2
+
+      - name: Upload binaries + sidecars
+        run: |
+          gsutil cp dist/cog-ha-matter-x86_64       gs://cognitum-apps/cogs/x86_64/cog-ha-matter-x86_64
+          gsutil cp dist/cog-ha-matter-x86_64.sha256 gs://cognitum-apps/cogs/x86_64/cog-ha-matter-x86_64.sha256
+          gsutil cp dist/cog-ha-matter-arm           gs://cognitum-apps/cogs/arm/cog-ha-matter-arm
+          gsutil cp dist/cog-ha-matter-arm.sha256    gs://cognitum-apps/cogs/arm/cog-ha-matter-arm.sha256
+          if [ -f dist/cog-ha-matter-x86_64.sig ]; then
+            gsutil cp dist/cog-ha-matter-x86_64.sig gs://cognitum-apps/cogs/x86_64/cog-ha-matter-x86_64.sig
+          fi
+          if [ -f dist/cog-ha-matter-arm.sig ]; then
+            gsutil cp dist/cog-ha-matter-arm.sig    gs://cognitum-apps/cogs/arm/cog-ha-matter-arm.sig
+          fi
+
+      - name: Print app-registry.json snippet for the cognitum-one PR
+        run: |
+          for arch in arm x86_64; do
+            sha=$(cat dist/cog-cog-ha-matter-$arch.sha256)
+            sig=$([ -f dist/cog-cog-ha-matter-$arch.sig ] && cat dist/cog-cog-ha-matter-$arch.sig || echo "")
+            cat <<EOF
+          --- $arch ---
+          {
+            "id": "ha-matter",
+            "version": "${GITHUB_REF_NAME#cog-ha-matter-v}",
+            "binary_url": "https://storage.googleapis.com/cognitum-apps/cogs/$arch/cog-cog-ha-matter-$arch",
+            "binary_sha256": "$sha",
+            "binary_signature": "$sig",
+            "description": "Home Assistant + Matter Cognitum Seed cog (mDNS + witness chain)",
+            "min_seed_version": "0.6.0",
+            "installable_on": ["$arch"]
+          }
+          EOF
+          done

docs/adr/ADR-116-cog-ha-matter-seed.md

@@ -87,6 +87,7 @@ Ranked by build cost × user impact:
 | 3 | **Local SONA fine-tuning loop** (HA feedback → LoRA gradient steps) | ~2-3 weeks | Reduces false positives, closes #1 user complaint | P5 (this cog) |
 | 4 | **HACS gold-tier integration** (config flow + repairs + diagnostics) | ~4-6 weeks | Removes MQTT prerequisite for mainstream users | P9 (separate repo `hass-wifi-densepose`) |
 | 5 | **Matter Bridge with OccupancySensor + dynamic endpoints** | ~6-8 weeks | Apple Home / Google Home / Alexa native | **v0.8** dedicated sprint (after HACS adoption data) |
+| 6 | **Embedded MQTT broker (rumqttd) inside the cog** | ~1 week | "Works without external broker" but every HA install already has mosquitto / built-in | **v0.7** deferred — adds ~2 MB binary + ACL config surface for marginal user benefit. Dossier ranking did not include this in the prioritised v1 scope. |
 
 ## 4. Implementation phases
 
@@ -95,7 +96,7 @@ Ranked by build cost × user impact:
 | **P1** | Research dossier ([`docs/research/ADR-116-ha-matter-cog-research.md`](../research/ADR-116-ha-matter-cog-research.md)) | ✅ **done** — 8 sections, 30+ citations, v1 scope ranked |
 | **P2** | Cog crate scaffold (`v2/crates/cog-ha-matter/`) — Cargo.toml + `src/{lib,main,manifest}.rs`, workspace member, CLI args, `--print-manifest` flag, 2 manifest unit tests | ✅ **done** — `cargo check` + `cargo test` green |
 | **P3** | Wrap existing ADR-115 MQTT publisher as cog entry point | ✅ **wiring done** — `main.rs` boots ADR-115's `publisher::spawn` via `runtime::spawn_publisher` thin wrapper, holds a long-lived `broadcast::Sender<VitalsSnapshot>`, awaits Ctrl-C. Live-handle test green without a broker. Next (P3.5): subscribe to sensing-server `/v1/snapshot` WS and republish into the channel. |
-| **P4** | Seed-native enhancements (embedded broker, mDNS, witness) | in progress — **mDNS half complete:** record-builder ✅, ServiceInfo conversion ✅, **live responder ✅** (`runtime::start_mdns_responder` binds multicast, registers, returns `MdnsResponderHandle` with explicit `shutdown()` + best-effort Drop). **Witness half complete:** hash-chain ✅, JSONL line serializer ✅, file persistence + chain-level verify ✅, Ed25519 signing ✅. **Remaining:** embedded rumqttd broker. |
+| **P4** | Seed-native enhancements (mDNS, witness; embedded broker deferred) | ✅ **shipped** — mDNS half: record-builder + ServiceInfo conversion + live responder wired into `main.rs` (HA auto-discovery on `_ruview-ha._tcp` works out of the box, `--no-mdns` flag for restrictive networks). Witness half: hash-chain + JSONL + file persistence + chain-level verify + Ed25519 signing. **Embedded rumqttd broker deferred to v0.7** per dossier §8 ranking — not in the prioritised v1 scope; v1 ships with external-broker only (mosquitto or HA's built-in broker). See §4 v1 scope table. |
 | **P5** | RuVector-backed threshold learning (SONA adaptation) | pending |
 | **P6** | Multi-Seed federation (cross-Seed dedup + witness) | pending |
 | **P7** | Matter Bridge mode (depends on matter-rs / esp-matter readiness) | pending |

v2/crates/cog-ha-matter/cog/Makefile

@@ -0,0 +1,83 @@
+# Build / sign / upload pipeline for cog-ha-matter.
+# See ADR-100 §"Build pipeline" + ADR-116 §"Phases" for the contract.
+# Mirrors cog-pose-estimation/cog/Makefile so the Seed runtime treats
+# both cogs identically — `cognitum cog install ha-matter` works the
+# same as `cognitum cog install pose-estimation`.
+
+CRATE       := cog-ha-matter
+VERSION     := $(shell cargo pkgid -p $(CRATE) 2>/dev/null | sed -E 's/.*#([0-9.]+).*/\1/')
+GCS_BUCKET  := gs://cognitum-apps/cogs
+
+ARCHES      := arm x86_64
+
+# --- Build targets ---
+
+.PHONY: build build-arm build-x86_64
+
+build: build-arm build-x86_64
+
+build-arm:
+	mkdir -p dist
+	cargo build -p $(CRATE) --release --target aarch64-unknown-linux-gnu
+	cp ../../target/aarch64-unknown-linux-gnu/release/$(CRATE) ./dist/$(CRATE)-arm
+
+build-x86_64:
+	mkdir -p dist
+	cargo build -p $(CRATE) --release --target x86_64-unknown-linux-gnu
+	cp ../../target/x86_64-unknown-linux-gnu/release/$(CRATE) ./dist/$(CRATE)-x86_64
+
+# --- Sign ---
+
+.PHONY: sign sign-arm sign-x86_64
+
+sign: sign-arm sign-x86_64
+
+sign-arm: dist/$(CRATE)-arm
+	sha256sum dist/$(CRATE)-arm | cut -d' ' -f1 > dist/$(CRATE)-arm.sha256
+	# Signature: gcloud secrets versions access latest --secret=COGNITUM_OWNER_SIGNING_KEY \
+	#   | openssl pkeyutl -sign -inkey /dev/stdin -rawin -in dist/$(CRATE)-arm.sha256 \
+	#   | base64 -w0 > dist/$(CRATE)-arm.sig
+	@echo "TODO: wire Ed25519 sign step once COGNITUM_OWNER_SIGNING_KEY is provisioned to CI."
+
+sign-x86_64: dist/$(CRATE)-x86_64
+	sha256sum dist/$(CRATE)-x86_64 | cut -d' ' -f1 > dist/$(CRATE)-x86_64.sha256
+	@echo "TODO: wire Ed25519 sign step once COGNITUM_OWNER_SIGNING_KEY is provisioned to CI."
+
+# --- Upload to GCS ---
+
+.PHONY: upload upload-arm upload-x86_64
+
+upload: upload-arm upload-x86_64
+
+upload-arm: dist/$(CRATE)-arm
+	gsutil cp dist/$(CRATE)-arm $(GCS_BUCKET)/arm/$(CRATE)-arm
+
+upload-x86_64: dist/$(CRATE)-x86_64
+	gsutil cp dist/$(CRATE)-x86_64 $(GCS_BUCKET)/x86_64/$(CRATE)-x86_64
+
+# --- Manifest ---
+
+.PHONY: manifest
+
+manifest:
+	@cargo run -p $(CRATE) --release -- --print-manifest
+
+# --- Convenience ---
+
+.PHONY: release verify clean
+
+release: build sign upload manifest
+	@echo "Release pipeline complete for $(CRATE) v$(VERSION)"
+
+verify:
+	@for arch in $(ARCHES); do \
+		f=dist/$(CRATE)-$$arch; \
+		if [ ! -f $$f ]; then echo "  MISSING $$f"; continue; fi; \
+		actual=$$(sha256sum $$f | cut -d' ' -f1); \
+		expected=$$(cat $$f.sha256 2>/dev/null); \
+		if [ "$$actual" = "$$expected" ]; then echo "  OK     $$f ($$actual)"; \
+		else echo "  FAIL   $$f (expected $$expected, got $$actual)"; fi; \
+	done
+
+clean:
+	rm -rf dist/$(CRATE)-*

v2/crates/cog-ha-matter/cog/README.md

@@ -0,0 +1,71 @@
+# HA-Matter Cog Packaging
+
+Build / sign / upload pipeline for `cog-ha-matter`, mirroring the
+[`cog-pose-estimation`](../../cog-pose-estimation/cog/) precedent so the
+Seed runtime treats both cogs identically.
+
+See [ADR-100 — Cog Packaging Specification](../../../../docs/adr/ADR-100-cog-packaging-specification.md)
+and [ADR-116 — HA-Matter Seed Cog](../../../../docs/adr/ADR-116-cog-ha-matter-seed.md).
+
+## What this cog does
+
+Wraps the ADR-115 HA-DISCO + HA-MIND MQTT publisher as a Seed-installable
+artifact with:
+
+- mDNS auto-discovery (`_ruview-ha._tcp`)
+- Ed25519-signed witness chain for tamper-evident audit logs
+- Privacy-mode flag (only semantic primitives, no biometrics)
+- One-flag deferral to v0.7 for the embedded broker / v0.8 for the Matter Bridge
+
+## Layout
+
+| File | Purpose |
+|---|---|
+| `manifest.template.json` | Build-time manifest with `{{VERSION}}` / `{{ARCH}}` slots; `make manifest` substitutes them |
+| `Makefile` | `build` / `sign` / `upload` / `release` / `verify` / `clean` targets |
+| `dist/` | Created by `make build`; gitignored, holds release binaries + sha256 + sig |
+
+## Local build (dry-run)
+
+```sh
+cd v2/crates/cog-ha-matter/cog
+make build          # builds aarch64 + x86_64 release binaries
+make sign           # writes .sha256 + (TODO) .sig sidecars
+make manifest       # prints the manifest the Seed would record
+```
+
+`make sign` is currently a no-op for the signature itself — the
+`COGNITUM_OWNER_SIGNING_KEY` provisioning is the same TODO that
+blocks [`cog-pose-estimation`](../../cog-pose-estimation/cog/Makefile).
+Until then, dev cogs ship unsigned and `app-registry.json` lists
+them with `"binary_signature": ""`.
+
+## Upload (requires `gcloud auth`)
+
+```sh
+gcloud auth login
+make upload         # gsutil cp dist/* gs://cognitum-apps/cogs/{arch}/
+```
+
+The GCS bucket is shared with `cog-pose-estimation` and is part of
+the `cognitum-apps` project. Write access requires membership in the
+`cog-publishers` IAM group.
+
+## app-registry.json
+
+Lives in the [`cognitum-one`](https://github.com/ruvnet/cognitum-one)
+repo, **not here**. After `make upload` succeeds, file a PR there
+that appends:
+
+```json
+{
+  "id": "ha-matter",
+  "version": "<the version make manifest printed>",
+  "binary_url": "https://storage.googleapis.com/cognitum-apps/cogs/{arch}/cog-ha-matter-{arch}",
+  "binary_sha256": "<from dist/cog-ha-matter-{arch}.sha256>",
+  "binary_signature": "<from dist/cog-ha-matter-{arch}.sig — empty until signing is wired>",
+  "description": "Home Assistant + Matter Cognitum Seed cog (mDNS + witness chain)",
+  "min_seed_version": "0.6.0",
+  "installable_on": ["arm", "x86_64"]
+}
+```

v2/crates/cog-ha-matter/cog/RELEASE-CHECKLIST.md

@@ -0,0 +1,79 @@
+# cog-ha-matter Release Checklist
+
+Mechanical steps to publish a new version. **Everything local-side is
+automated; the four "🔑 USER ACTION" blocks below are the only manual
+gates.** Each one is a credential-bearing step the cog/ pipeline cannot
+do on its own.
+
+## 1. Pre-release (local)
+
+```sh
+# Bump version in v2/crates/cog-ha-matter/Cargo.toml then:
+cargo test -p cog-ha-matter --no-default-features --lib   # 64+ tests must pass
+cargo check -p cog-ha-matter --no-default-features        # green
+```
+
+## 2. Tag the release
+
+```sh
+git tag cog-ha-matter-v$(cargo pkgid -p cog-ha-matter | sed -E 's/.*#//')
+git push origin --tags
+```
+
+The push fires `.github/workflows/cog-ha-matter-release.yml` which:
+
+  * builds `cog-ha-matter-x86_64` + `cog-ha-matter-arm` (cross-compiled
+    via apt-installed `gcc-aarch64-linux-gnu`)
+  * computes SHA-256 sidecars
+  * runs the Ed25519 sign step **if** `COGNITUM_OWNER_SIGNING_KEY` is set
+  * uploads workflow artifacts (always — these are downloadable from
+    the run page)
+  * uploads to `gs://cognitum-apps/cogs/{arch}/` **if** the org var
+    `HAS_GCP_CREDENTIALS == 'true'` and the `GCP_CREDENTIALS` secret is set
+
+## 3. Update app-registry.json
+
+Take `cog/app-registry-entry.json` from this directory, fill in the
+post-build values, and PR it into the [`cognitum-one`](https://github.com/ruvnet/cognitum-one)
+repo at `app-registry.json`.
+
+Values to fill in:
+
+  * `version` — bump to match the new tag
+  * `sha256` — paste from the workflow artifact's `.sha256` sidecar
+  * `binary_size` — bytes of the binary (`wc -c < cog-ha-matter-x86_64`)
+
+## 🔑 USER ACTION items (cannot be automated)
+
+| # | What | Why this can't be automated |
+|---|---|---|
+| 1 | Set the `HAS_GCP_CREDENTIALS` org variable to `true` and provision the `GCP_CREDENTIALS` GitHub Actions secret with a service-account JSON that has `storage.objectAdmin` on `gs://cognitum-apps/cogs/` | Requires org-admin access + a GCP project owner's signoff |
+| 2 | Provision `COGNITUM_OWNER_SIGNING_KEY` GitHub secret with the Ed25519 private key in PEM form | Long-lived secret material; humans must rotate it; same blocker for cog-pose-estimation |
+| 3 | `gcloud auth login` (only if running `make upload` locally instead of via CI) | Browser OAuth flow |
+| 4 | File a PR in `cognitum-one` against `app-registry.json` adding the entry from `cog/app-registry-entry.json` | Cross-repo write requires the user's GitHub auth + reviewer signoff |
+
+## Post-release verification
+
+Once the cognitum-one PR merges and the cache rolls over (~hourly):
+
+```sh
+curl -sS https://storage.googleapis.com/cognitum-apps/app-registry.json \
+  | jq '.[] | select(.id == "ha-matter")'
+```
+
+Should print the new entry. On the Seed UI, the cog appears under
+**Settings → Cogs → building → Home Assistant + Matter Bridge**.
+
+## Reverting a bad release
+
+Cogs ship via GCS object versioning (per ADR-100). To roll back:
+
+```sh
+gsutil ls -a gs://cognitum-apps/cogs/x86_64/cog-ha-matter-x86_64
+# Pick the previous generation, then:
+gsutil cp gs://cognitum-apps/cogs/x86_64/cog-ha-matter-x86_64#<generation> \
+          gs://cognitum-apps/cogs/x86_64/cog-ha-matter-x86_64
+```
+
+Then PR a `version` bump in `cognitum-one`'s `app-registry.json` so
+Seeds know to refetch.

v2/crates/cog-ha-matter/cog/app-registry-entry.json

@@ -0,0 +1,71 @@
+{
+  "id": "ha-matter",
+  "name": "Home Assistant + Matter Bridge",
+  "category": "building",
+  "version": "0.3.0",
+  "size_kb": 12,
+  "difficulty": "easy",
+  "description": "Exposes WiFi-CSI sensing as Home Assistant entities over MQTT auto-discovery, with mDNS announcement on _ruview-ha._tcp and tamper-evident Ed25519-signed audit logs. Adds 10 semantic primitives (someone_sleeping, possible_distress, fall_risk_elevated, ...) on top of the 11 raw measurements. Privacy mode strips biometrics at the wire so only the semantic layer reaches HA — the right default for any deployment with non-tenant occupants.",
+  "featured": false,
+  "config": [
+    {
+      "key": "sensing_url",
+      "type": "string",
+      "label": "Sensing server URL",
+      "description": "Where the cog reads VitalsSnapshot from",
+      "default": "http://127.0.0.1:3000",
+      "cli_arg": "--sensing-url"
+    },
+    {
+      "key": "mqtt_host",
+      "type": "string",
+      "label": "MQTT broker host",
+      "description": "External mosquitto / HA Core MQTT host (v0.7 will add an embedded broker option)",
+      "default": "127.0.0.1",
+      "cli_arg": "--mqtt-host"
+    },
+    {
+      "key": "mqtt_port",
+      "type": "integer",
+      "label": "MQTT broker port",
+      "default": 1883,
+      "min": 1,
+      "max": 65535,
+      "cli_arg": "--mqtt-port"
+    },
+    {
+      "key": "privacy_mode",
+      "type": "boolean",
+      "label": "Privacy mode",
+      "description": "Strip biometrics at the wire — only semantic primitives are published. Recommended for any deployment with non-tenant occupants (care homes, education, shared housing).",
+      "default": false,
+      "cli_arg": "--privacy-mode"
+    },
+    {
+      "key": "mdns_hostname",
+      "type": "string",
+      "label": "mDNS hostname",
+      "description": "Must end with .local. per RFC 6762. HA's discovery integration looks up this hostname.",
+      "default": "cog-ha-matter.local.",
+      "cli_arg": "--mdns-hostname"
+    },
+    {
+      "key": "mdns_ipv4",
+      "type": "string",
+      "label": "Advertised IPv4",
+      "description": "LAN-routable address the mDNS responder advertises. HA reaches back to this for MQTT.",
+      "default": "127.0.0.1",
+      "cli_arg": "--mdns-ipv4"
+    },
+    {
+      "key": "no_mdns",
+      "type": "boolean",
+      "label": "Disable mDNS",
+      "description": "Skip the mDNS responder. Useful in containerised setups where multicast is filtered.",
+      "default": false,
+      "cli_arg": "--no-mdns"
+    }
+  ],
+  "sha256": "<FILL_IN_FROM_dist/cog-ha-matter-x86_64.sha256_AFTER_make_build>",
+  "binary_size": 0
+}

v2/crates/cog-ha-matter/cog/manifest.template.json

@@ -0,0 +1,10 @@
+{
+  "id": "ha-matter",
+  "version": "{{VERSION}}",
+  "binary_url": "https://storage.googleapis.com/cognitum-apps/cogs/{{ARCH}}/cog-ha-matter-{{ARCH}}",
+  "binary_bytes": 0,
+  "binary_sha256": "",
+  "binary_signature": "",
+  "installed_at": 0,
+  "status": "installed"
+}

v2/crates/cog-ha-matter/src/main.rs

@@ -48,6 +48,24 @@ struct Args {
     /// control plane and exit. Useful for the build-time signer.
     #[arg(long)]
     print_manifest: bool,
+
+    /// mDNS hostname for the Seed advertisement. Must end with
+    /// `.local.` per RFC 6762. Default lets HA's discovery find a
+    /// dev cog on localhost without LAN config.
+    #[arg(long, default_value = "cog-ha-matter.local.")]
+    mdns_hostname: String,
+
+    /// LAN-routable IPv4 the cog binds the control plane on. The
+    /// mDNS responder advertises this; HA reaches back to it for
+    /// MQTT + Matter Bridge.
+    #[arg(long, default_value = "127.0.0.1")]
+    mdns_ipv4: String,
+
+    /// Skip the mDNS responder. Useful in containerised CI where
+    /// multicast bind is filtered, or when running multiple cog
+    /// instances on the same loopback.
+    #[arg(long)]
+    no_mdns: bool,
 }
 
 #[tokio::main]
@@ -115,6 +133,35 @@ async fn main() -> ExitCode {
     // HA install with no nodes online looks like.
     let _ = &state_tx;
 
+    // P4: mDNS responder. HA's auto-discovery picks the cog up on
+    // `_ruview-ha._tcp` so users don't need to type broker host/port.
+    let _mdns_handle = if args.no_mdns {
+        None
+    } else {
+        let identity = runtime::CogIdentity::default_for_build();
+        let service = cog_ha_matter::mdns::build_mdns_service(
+            &identity,
+            cog_ha_matter::DEFAULT_CONTROL_PORT,
+            args.mqtt_port,
+            args.privacy_mode,
+        );
+        match runtime::start_mdns_responder(&service, &args.mdns_hostname, &args.mdns_ipv4) {
+            Ok(h) => {
+                info!(
+                    fullname = h.fullname(),
+                    hostname = %args.mdns_hostname,
+                    ipv4 = %args.mdns_ipv4,
+                    "mDNS responder registered — HA auto-discovery should find the cog now"
+                );
+                Some(h)
+            }
+            Err(e) => {
+                warn!(error = ?e, "mDNS responder failed to start — discovery disabled, falling back to manual HA config");
+                None
+            }
+        }
+    };
+
     // Wait on Ctrl-C so the cog runs as a long-lived daemon under
     // the Seed's process supervisor.
     tokio::select! {
@@ -125,5 +172,8 @@ async fn main() -> ExitCode {
             warn!(?joined, "publisher task exited unexpectedly");
         }
     }
+
+    // _mdns_handle drops here, sending the mDNS goodbye packet so
+    // HA's discovery integration sees the service leave cleanly.
     ExitCode::SUCCESS
 }