ci: replace upstream's GHCR release workflow with a Gitea CI (tests + image build)

Upstream's build.yaml pushes to ghcr.io and has failed on every push since the
fork — those reds were never ours. Gitea now runs the 17 tests and a docker
build with no push.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014LCQmFvKshyAJsE8C3B5ET

.gitea/workflows/ci.yml

@@ -0,0 +1,19 @@
+# Gitea CI for the OTM fork: the unit + Flask tests, then prove the image builds.
+# Upstream's .github/workflows/build.yaml pushed to GHCR and could never pass here.
+name: CI
+on:
+  push:
+  pull_request:
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container: python:3.13-slim
+    steps:
+      - uses: actions/checkout@v4
+      - run: pip install -q -r requirements.txt
+      - run: cd app && python -m unittest -v
+  image:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: docker build -t 13ft-ci:${{ gitea.sha }} .

.github/workflows/build.yaml

@@ -1,79 +0,0 @@
-name: Build
-
-# Controls when the workflow will run
-on:
-  workflow_dispatch:
-  push:
-    branches:
-      - 'main'
-      - 'dev'
-    tags:
-      - 'v*.*.*'
-  pull_request:
-    branches:
-      - 'main'
-      - 'dev'
-
-# permissions are needed if pushing to ghcr.io
-permissions: 
-  packages: write
-
-jobs:
-  build:
-    name: "Build and release"
-    runs-on: ubuntu-latest
-    steps:
-      # Get the repository's code
-      - name: ⬇️ checkout
-        uses: actions/checkout@v2
-
-      # https://github.com/docker/setup-qemu-action
-      - name: ⚙ set up qemu
-        uses: docker/setup-qemu-action@v1
-
-      # https://github.com/docker/setup-buildx-action
-      - name: ⚙ set up docker buildx
-        id: buildx
-        uses: docker/setup-buildx-action@v1
-      
-      - name: 👤 login to ghcr
-        if: github.event_name != 'pull_request'
-        uses: docker/login-action@v1
-        with:
-          registry: ghcr.io
-          username: ${{ github.repository_owner }}
-          password: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: 👤 login to docker hub
-        if: github.event_name != 'pull_request'
-        uses: docker/login-action@v1
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: 🏷 docker meta
-        id: docker_meta # you'll use this in the next step
-        uses: docker/metadata-action@v3
-        with:
-          # list of Docker images to use as base name for tags
-          images: |
-            ghcr.io/${{ github.repository_owner }}/13ft
-            docker.io/wasimaster/13ft
-          # Docker tags based on the following events/attributes
-          tags: |
-            type=schedule
-            type=ref,event=branch
-            type=ref,event=pr
-            type=semver,pattern={{version}}
-            type=semver,pattern={{major}}.{{minor}}
-            type=semver,pattern={{major}}
-            type=sha
-  
-      - name: 📦 build and ⬆ push
-        uses: docker/build-push-action@v2
-        with:
-          context: .
-          platforms: linux/amd64,linux/arm/v7,linux/arm64
-          push: ${{ github.event_name != 'pull_request' }}
-          tags: ${{ steps.docker_meta.outputs.tags }}
-          labels: ${{ steps.docker_meta.outputs.labels }}