feat: add video_analyze tool for native video understanding (#19301)

* feat: add video_analyze tool for native video understanding

Adds a video_analyze tool that sends video files to multimodal LLMs
(e.g. Gemini) for analysis via the OpenRouter-compatible video_url
content type. Mirrors vision_analyze in structure, error handling,
and registration pattern.

Key design:
- Base64 encodes entire video (no frame extraction, no ffmpeg dep)
- Uses 'video_url' content block type (OpenRouter standard)
- Supports mp4, webm, mov, avi, mkv, mpeg formats
- 50 MB hard cap, 20 MB warning threshold
- 180s minimum timeout (videos take longer than images)
- AUXILIARY_VIDEO_MODEL env override, falls back to AUXILIARY_VISION_MODEL
- Same SSRF protection, retry logic, and cleanup as vision_analyze

Default disabled: registered in 'video' toolset (not in _HERMES_CORE_TOOLS).
Users opt in via: hermes tools enable video, or enabled_toolsets=['video'].

* feat(video): add models.dev capability pre-check + CONFIGURABLE_TOOLSETS entry

- Pre-checks model video capability via models.dev modalities.input
  before expensive base64 encoding. Fails early with helpful message
  suggesting video-capable alternatives (gemini, mimo-v2.5-pro).
- Passes optimistically if model unknown or lookup fails.
- Adds ModelInfo.supports_video_input() helper.
- Adds 'video' to CONFIGURABLE_TOOLSETS and _DEFAULT_OFF_TOOLSETS
  so 'hermes tools enable video' works from CLI.
- 8 new tests for the capability check (37 total).

* refactor(video): remove models.dev capability pre-check

Removes _check_video_model_capability and ModelInfo.supports_video_input.
The vision_analyze tool doesn't pre-check image capability either — both
tools rely on the same pattern: send request, handle API errors gracefully
with categorized user-facing messages. The pre-check was inconsistent
(only worked for some providers/models) so drop it for parity.

* cleanup: compress comments, fix fragile timeout coupling

- Replace _VISION_DOWNLOAD_TIMEOUT * 2 with hardcoded 60s (no silent
  breakage if vision timeout changes independently)
- Strip verbose comments and redundant log lines throughout
- No behavioral changes

hermes_cli/tools_config.py

@@ -56,6 +56,7 @@ CONFIGURABLE_TOOLSETS = [
     ("file",            "📁 File Operations",           "read, write, patch, search"),
     ("code_execution",  "⚡ Code Execution",            "execute_code"),
     ("vision",          "👁️  Vision / Image Analysis",  "vision_analyze"),
+    ("video",           "🎬 Video Analysis",            "video_analyze (requires video-capable model)"),
     ("image_gen",       "🎨 Image Generation",          "image_generate"),
     ("moa",             "🧠 Mixture of Agents",         "mixture_of_agents"),
     ("tts",             "🔊 Text-to-Speech",            "text_to_speech"),
@@ -78,7 +79,7 @@ CONFIGURABLE_TOOLSETS = [
 # Toolsets that are OFF by default for new installs.
 # They're still in _HERMES_CORE_TOOLS (available at runtime if enabled),
 # but the setup checklist won't pre-select them for first-time users.
-_DEFAULT_OFF_TOOLSETS = {"moa", "homeassistant", "rl", "spotify", "discord", "discord_admin"}
+_DEFAULT_OFF_TOOLSETS = {"moa", "homeassistant", "rl", "spotify", "discord", "discord_admin", "video"}
 
 # Platform-scoped toolsets: only appear in the `hermes tools` checklist for
 # these platforms, and only resolve/save for these platforms.  A toolset