v2.0.0 — Pure glue architecture: zero copied code, pluggable channels

BREAKING: Complete architectural rewrite.

Before: Copied x-reader's fetcher code into readers/ (1205 lines of borrowed code)
After: Pluggable channel system where each channel is a thin wrapper (~50 lines)
       around the best external tool for that platform. Zero copied code.

Architecture:
- channels/base.py — Universal Channel interface (read, search, check)
- channels/web.py — Jina Reader API (swappable)
- channels/github.py — GitHub API (swappable)
- channels/twitter.py — birdx + Jina fallback (swappable)
- channels/youtube.py — yt-dlp (swappable)
- channels/reddit.py — Reddit JSON API + proxy (swappable)
- channels/rss.py — feedparser (swappable)
- channels/bilibili.py — Bilibili API (swappable)
- channels/exa_search.py — Exa semantic search (swappable)

Key design: every backend can be swapped by changing ONE file.
YouTube dies? Change youtube.py. Exa sucks? Swap exa_search.py for Tavily.
Nothing else changes.

Removed: reader.py, schema.py, readers/, search/, utils/ (all x-reader code)
Tests: 36/36 passing

agent_eyes/channels/youtube.py

@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+"""YouTube — via yt-dlp (free, pip install yt-dlp).
+
+Backend: yt-dlp (https://github.com/yt-dlp/yt-dlp)
+Swap to: any YouTube subtitle extractor
+"""
+
+import json
+import shutil
+import subprocess
+import tempfile
+from pathlib import Path
+from urllib.parse import urlparse, parse_qs
+from .base import Channel, ReadResult
+
+
+class YouTubeChannel(Channel):
+    name = "youtube"
+    description = "YouTube video transcripts"
+    backends = ["yt-dlp"]
+    requires_tools = ["yt-dlp"]
+    tier = 0
+
+    def can_handle(self, url: str) -> bool:
+        domain = urlparse(url).netloc.lower()
+        return "youtube.com" in domain or "youtu.be" in domain
+
+    async def read(self, url: str, config=None) -> ReadResult:
+        if not shutil.which("yt-dlp"):
+            raise RuntimeError("yt-dlp not installed. Install: pip install yt-dlp")
+
+        with tempfile.TemporaryDirectory() as tmpdir:
+            # Get video info
+            info = self._get_info(url)
+            title = info.get("title", url)
+            author = info.get("uploader", "")
+
+            # Try to get subtitles
+            transcript = self._get_subtitles(url, tmpdir)
+
+            if not transcript:
+                transcript = f"[Video: {title}]\n[No subtitles available. Use Groq Whisper for transcription.]"
+
+            return ReadResult(
+                title=title,
+                content=transcript,
+                url=url,
+                author=author,
+                platform="youtube",
+                extra={
+                    "duration": info.get("duration"),
+                    "view_count": info.get("view_count"),
+                    "upload_date": info.get("upload_date"),
+                },
+            )
+
+    def _get_info(self, url: str) -> dict:
+        try:
+            result = subprocess.run(
+                ["yt-dlp", "--dump-json", "--no-download", url],
+                capture_output=True, text=True, timeout=30,
+            )
+            if result.returncode == 0:
+                return json.loads(result.stdout)
+        except (subprocess.TimeoutExpired, json.JSONDecodeError):
+            pass
+        return {}
+
+    def _get_subtitles(self, url: str, tmpdir: str) -> str:
+        """Extract subtitles using yt-dlp."""
+        try:
+            subprocess.run(
+                ["yt-dlp", "--write-auto-sub", "--write-sub",
+                 "--sub-lang", "en,zh-Hans,zh",
+                 "--skip-download", "--sub-format", "vtt",
+                 "-o", f"{tmpdir}/%(id)s.%(ext)s", url],
+                capture_output=True, text=True, timeout=30,
+            )
+
+            # Find and read subtitle file
+            for f in Path(tmpdir).glob("*.vtt"):
+                text = f.read_text(errors="replace")
+                # Strip VTT headers and timestamps
+                lines = []
+                for line in text.split("\n"):
+                    line = line.strip()
+                    if not line or line.startswith("WEBVTT") or "-->" in line or line.isdigit():
+                        continue
+                    if line not in lines[-1:]:  # deduplicate
+                        lines.append(line)
+                return "\n".join(lines)
+        except subprocess.TimeoutExpired:
+            pass
+        return ""