refactor: convert plugin tools to skills/ directory structure

Replace "tools" shell script declarations with proper skills/ directory
so Claude Code injects them into system-reminder and Skill tool can invoke them.

Each tool now has its own skills/<name>/SKILL.md with usage prompt.
Remove "type" and "tools" fields from plugin manifests.
Bump version to 1.0.3.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

fission-python/skills/update-docstring/SKILL.md

@@ -0,0 +1,48 @@
+---
+name: update-docstring
+description: View or update the Fission configuration embedded in a Python function's docstring
+---
+
+View or update Fission configuration in a Python function docstring using the update-docstring script.
+
+## Usage
+
+```bash
+# View current config
+./fission-python/update-docstring.sh <file.py> <function-name> --get
+
+# Update config
+./fission-python/update-docstring.sh <file.py> <function-name> --set '<json>'
+```
+
+## Docstring format
+
+The script reads/writes Fission config between ` ```fission ` and ` ``` ` markers:
+
+```python
+def main():
+    """
+    ```fission
+    {
+        "name": "function-name",
+        "http_triggers": {
+            "trigger-name": {"url": "/endpoint", "methods": ["GET"]}
+        }
+    }
+    ```
+    """
+```
+
+## Examples
+
+User asks: "Show the Fission config of function `main` in `./my-api/src/func.py`"
+
+```bash
+./fission-python/update-docstring.sh ./my-api/src/func.py main --get
+```
+
+User asks: "Update the HTTP trigger URL to `/v2/items`"
+
+```bash
+./fission-python/update-docstring.sh ./my-api/src/func.py main --set '{"http_triggers": {"api": {"url": "/v2/items", "methods": ["GET"]}}}'
+```