fix(ci): resolve lint errors, upgrade actions to Node.js 24

- Remove extraneous f-string prefixes (compose.py, init.py)
- Remove unused variable and imports (validate.py, test_validate.py)
- Upgrade checkout@v4→v6, setup-python@v5→v6 in ci.yml

Made-with: Cursor

Author: jmjava

.github/workflows/ci.yml

@@ -14,8 +14,8 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.12"
       - run: pip install ruff
@@ -27,8 +27,8 @@ jobs:
       matrix:
         python-version: ["3.10", "3.11", "3.12"]
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - run: pip install ".[dev]"
@@ -37,8 +37,8 @@ jobs:
   e2e:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v6
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.12"
       - run: pip install ".[dev]"

src/docgen/compose.py

@@ -69,7 +69,7 @@ def _compose_simple(self, seg_id: str, video_path: Path, *, strict: bool = True)
         audio_dur = self._probe_duration(audio)
         video_dur = self._probe_duration(video_path)
         if audio_dur is None or video_dur is None:
-            print(f"    SKIP: cannot probe durations")
+            print("    SKIP: cannot probe durations")
             return False
 
         freeze = self.check_freeze_ratio(audio_dur, video_dur)

src/docgen/init.py

@@ -385,7 +385,7 @@ def _write_wrapper_scripts(plan: InitPlan) -> list[str]:
 
 
 def _write_narration_readme(plan: InitPlan) -> str:
-    content = textwrap.dedent(f"""\
+    content = textwrap.dedent("""\
         # Narration scripts (TTS source)
 
         These Markdown files are the spoken script for demo segments.

src/docgen/validate.py

@@ -196,7 +196,6 @@ def _check_blank_frames(
         if not samples:
             return CheckResult("blank_frames", False, ["No frames sampled"])
 
-        duration = samples[-1][0] - samples[0][0] if len(samples) > 1 else 0
         dark_threshold = 15
         dark_count = 0
         dark_ranges: list[str] = []

tests/test_validate.py

@@ -6,11 +6,8 @@
 
 from __future__ import annotations
 
-import json
 import subprocess
-import tempfile
 from pathlib import Path
-from unittest.mock import patch
 
 import cv2
 import numpy as np
@@ -19,7 +16,7 @@
 
 from docgen.compose import ComposeError, Composer
 from docgen.config import Config
-from docgen.validate import CheckResult, Validator, _sample_frames
+from docgen.validate import Validator, _sample_frames
 
 
 # ── Helpers: create synthetic test videos ─────────────────────────────
@@ -357,7 +354,7 @@ def _make_silent_audio(path: Path, duration_sec: float = 10.0) -> Path:
     subprocess.run(
         [
             "ffmpeg", "-y", "-f", "lavfi",
-            "-i", f"anullsrc=r=44100:cl=mono",
+            "-i", "anullsrc=r=44100:cl=mono",
             "-t", str(duration_sec),
             "-c:a", "libmp3lame", "-b:a", "32k",
             str(path),