feat: add podcast generation skill

- Add podcast-generation skill for creating tech explainer podcasts
- Include generate.py script with TTS synthesis capabilities
- Add tech-explainer template for structured podcast content
- Increase sandbox command timeout from 30s to 600s to support
  longer-running skill scripts

skills/public/podcast-generation/templates/tech-explainer.md

@@ -0,0 +1,63 @@
+# Tech Explainer Podcast Template
+
+Use this template when converting technical documentation, API guides, or developer tutorials into podcasts.
+
+## Input Preparation
+
+When the user wants to convert technical content to a podcast, help them structure the input:
+
+1. **Simplify Code Examples**: Replace code snippets with plain language descriptions
+   - Instead of showing actual code, describe what the code does
+   - Focus on concepts rather than syntax
+
+2. **Remove Complex Notation**:
+   - Mathematical formulas should be explained in words
+   - API endpoints described by function rather than URL paths
+   - Configuration examples summarized as settings descriptions
+
+3. **Add Context**:
+   - Explain why the technology matters
+   - Include real-world use cases
+   - Add analogies for complex concepts
+
+## Example Transformation
+
+### Original Technical Content:
+```markdown
+# Using the API
+
+POST /api/v1/users
+{
+  "name": "John",
+  "email": "john@example.com"
+}
+
+Response: 201 Created
+```
+
+### Podcast-Ready Content:
+```markdown
+# Creating Users with the API
+
+The user creation feature allows applications to register new users in the system.
+When you want to add a new user, you send their name and email address to the server.
+If everything goes well, the server confirms the user was created successfully.
+This is commonly used in signup flows, admin dashboards, or when importing users from other systems.
+```
+
+## Generation Command
+
+```bash
+python /mnt/skills/public/podcast-generation/scripts/generate.py \
+  --input-file /mnt/user-data/workspace/tech-content.md \
+  --output-file /mnt/user-data/outputs/tech-explainer-podcast.mp3 \
+  --locale en
+```
+
+## Tips for Technical Podcasts
+
+- Keep episodes focused on one main concept
+- Use analogies to explain abstract concepts
+- Include practical "why this matters" context
+- Avoid jargon without explanation
+- Make the dialogue accessible to beginners