fix(test): make test-quick reliable as developer gate

Fixes for D-001验收问题:
1. test-quick.sh: use set -euo pipefail, uv run ruff, no tail pipe
2. Remove unused imports in factories (app.py, platform.py, provider.py)
3. Fix unused variable in smoke test
4. Add noqa: E402 to test_n8nsvapi.py lazy imports
5. Update smoke test docs: "minimal fake flow" not full pipeline

Now test-quick is a reliable gate: lint failures exit 1, test failures propagate.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

scripts/test-quick.sh

@@ -4,31 +4,30 @@
 # Runs linting, unit tests, and smoke tests without requiring real provider keys
 # Suitable for local branch validation
 
-set -e
+set -euo pipefail
 
 echo "=== LangBot Quick Self-Test ==="
 echo ""
 
 # 1. Ruff check
 echo "[1/3] Running ruff check..."
-if command -v ruff &> /dev/null; then
-    ruff check src/langbot/ tests/ --quiet || {
-        echo "⚠ Ruff check found issues. Run 'ruff check --fix' to auto-fix."
-    }
-else
-    echo "⚠ ruff not installed, skipping lint check"
-fi
+uv run ruff check src/langbot/ tests/ --output-format=concise || {
+    echo ""
+    echo "⚠ Ruff check found issues. Run 'uv run ruff check --fix' to auto-fix."
+    exit 1
+}
+echo "✓ Ruff check passed"
 echo ""
 
 # 2. Unit tests
 echo "[2/3] Running unit tests..."
-uv run pytest tests/unit_tests/ -q --tb=short 2>&1 | tail -5
+uv run pytest tests/unit_tests/ -q --tb=short
 echo ""
 
 # 3. Smoke tests (if exists)
 echo "[3/3] Running smoke tests..."
 if [ -d "tests/smoke" ]; then
-    uv run pytest tests/smoke/ -q --tb=short 2>&1 | tail -5
+    uv run pytest tests/smoke/ -q --tb=short
 else
     echo "No smoke tests found, skipping"
 fi