Generate diagram workflow - closes #1244

Author: fizyk

.github/workflows/diagram.yml

@@ -0,0 +1,27 @@
+name: Render Mermaid Diagrams
+on:
+  push:
+    paths:
+      - 'docs/*.mmd' # Trigger only when mermaid files change
+
+jobs:
+  render:
+    runs-on: ubuntu-latest
+    # Grant the action permission to write to the repository
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Install Mermaid CLI
+        run: npm install -g @mermaid-js/mermaid-cli
+
+      - name: Render Diagram
+        run: mmdc -p docs/puppeteer-config.json -i docs/architecture.mmd -o docs/images/architecture.svg -t neutral
+
+      - name: Commit and Push
+        uses: stefanzweifel/git-auto-commit-action@v7
+        with:
+          commit_message: "docs: update rendered mermaid diagram [skip ci]"
+          file_pattern: 'docs/images/*.svg'

.pre-commit-config.yaml

@@ -19,6 +19,7 @@ repos:
       - id: mixed-line-ending
       - id: check-yaml
       - id: pretty-format-json
+        args: [--autofix]
       - id: detect-private-key
       - id: debug-statements
 

docs/architecture.mmd

@@ -0,0 +1,19 @@
+sequenceDiagram
+    autonumber
+    participant Pytest as Pytest runner
+    participant ProcFactory as postgresql_proc_factory
+    participant PgServer as PostgreSQL process
+    participant TemplateDB as Template DB (seeded)
+    participant TestDB as Per-test DB (clone)
+
+    Pytest->>ProcFactory: request postgresql_proc with load=[load_database]
+    ProcFactory->>PgServer: start server
+    ProcFactory->>TemplateDB: invoke load_database (create metadata, seed data)
+    Note right of TemplateDB: Template is created and seeded once per full run
+    loop per test
+        Pytest->>PgServer: request clone of TemplateDB
+        PgServer->>TestDB: create cloned database for test
+        Pytest->>TestDB: run test using cloned DB
+        Pytest->>TestDB: teardown: commit transaction
+        Pytest->>TestDB: teardown: drop_all metadata (cleanup)
+    end

docs/images/.keep

@@ -0,0 +1,6 @@
+{
+  "args": [
+    "--no-sandbox",
+    "--disable-setuid-sandbox"
+  ]
+}