fix(ci): authenticate tramiton-core fetch in the agent image build (main deploys) (#143)

The PR `check` job authenticates the private tramiton-core git fetch, but the main-branch **`deploy-agent`** job builds `Dockerfile.agent` where cargo also fetches tramiton-core — inside the image build, with no credentials — so **agent image builds on main fail**.

Fix: inject the PAT as a **BuildKit secret** (never baked into an image layer).
- `Dockerfile.agent`: `RUN --mount=type=secret,id=tramiton_token …` applies the same `https`-insteadOf rewrite + `CARGO_NET_GIT_FETCH_WITH_CLI=true` before `cargo build`.
- `deploy-agent`: `DOCKER_BUILDKIT=1 docker build --secret id=tramiton_token,env=TRAMITON_FETCH_TOKEN …`, reusing the existing `TRAMITON_FETCH_TOKEN` secret.

Only the agent image depends on tramiton-core (dashboard/mcp/docs unaffected). **Self-tests on merge** — changing `Dockerfile.agent` makes `detect-changes` run `deploy-agent`.

Note: couldn't fully run the image build locally (no PAT value on hand + no `.dockerignore` so the context is large), but this mirrors the working PR-stage auth and uses standard BuildKit secret injection. Assumes the deploy runner's Docker daemon supports BuildKit (docker:27-cli → yes).
---------

Co-authored-by: Sharang Parnerkar <30073382+mighty840@users.noreply.github.com>
Reviewed-on: #143

.gitea/workflows/ci.yml

@@ -191,13 +191,18 @@ jobs:
       image: docker:27-cli
     steps:
       - name: Build, push and trigger orca redeploy
+        env:
+          # PAT for fetching the private tramiton-core git dependency during the
+          # image build (injected as a BuildKit secret, never baked into a layer).
+          TRAMITON_FETCH_TOKEN: ${{ secrets.TRAMITON_FETCH_TOKEN }}
         run: |
           apk add --no-cache git curl openssl
           git init && git remote add origin "${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}.git"
           git fetch --depth=1 origin "${GITHUB_SHA}" && git checkout FETCH_HEAD
           IMAGE=registry.meghsakha.com/compliance-agent
           echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login registry.meghsakha.com -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin
-          docker build -f Dockerfile.agent -t "$IMAGE:latest" -t "$IMAGE:${GITHUB_SHA}" .
+          DOCKER_BUILDKIT=1 docker build --secret id=tramiton_token,env=TRAMITON_FETCH_TOKEN \
+            -f Dockerfile.agent -t "$IMAGE:latest" -t "$IMAGE:${GITHUB_SHA}" .
           docker push "$IMAGE:latest" && docker push "$IMAGE:${GITHUB_SHA}"
           PAYLOAD=$(printf '{"ref":"refs/heads/main","repository":{"full_name":"sharang/compliance-scanner-agent"},"head_commit":{"id":"%s","message":"deploy agent"}}' "${GITHUB_SHA}")
           SIG=$(printf '%s' "$PAYLOAD" | openssl dgst -sha256 -hmac "${{ secrets.ORCA_WEBHOOK_SECRET }}" | awk '{print $2}')

Dockerfile.agent

@@ -2,7 +2,16 @@ FROM rust:1.94-bookworm AS builder
 
 WORKDIR /app
 COPY . .
-RUN cargo build --release -p compliance-agent
+# compliance-agent depends on the private tramiton-core git repo. Authenticate
+# the fetch with a PAT passed as a BuildKit secret (never baked into a layer).
+# Build with: DOCKER_BUILDKIT=1 docker build --secret id=tramiton_token,env=TRAMITON_FETCH_TOKEN ...
+RUN --mount=type=secret,id=tramiton_token \
+    if [ -s /run/secrets/tramiton_token ]; then \
+      git config --global \
+        url."https://sharang:$(cat /run/secrets/tramiton_token)@gitea.meghsakha.com/".insteadOf \
+        "ssh://git@gitea.meghsakha.com:22222/"; \
+    fi && \
+    CARGO_NET_GIT_FETCH_WITH_CLI=true cargo build --release -p compliance-agent
 
 FROM debian:bookworm-slim
 RUN apt-get update && apt-get install -y ca-certificates libssl3 git curl python3 python3-pip npm golang-go php-cli && rm -rf /var/lib/apt/lists/*