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/create-project/SKILL.md

@@ -0,0 +1,32 @@
+---
+name: create-project
+description: Create a new Fission Python project from the standard template
+---
+
+Create a new Fission Python project by running the create-project script.
+
+## Usage
+
+Run the following command from the repository root:
+
+```bash
+./fission-python/create-project.sh <project-name> [destination-directory]
+```
+
+- `project-name`: Name for the new project (letters, numbers, hyphens, underscores only)
+- `destination-directory`: Where to create the project (default: current directory)
+
+## What it does
+
+1. Copies the template from `fission-python/template/`
+2. Substitutes project name in `.fission/deployment.json`, override files, `src/helpers.py`, and `README.md`
+3. Validates the created project structure (build.sh, requirements.txt, workflows, docstrings)
+4. Creates a `.env` file with default environment variables
+
+## Example
+
+User asks: "Create a new Fission project called my-api in ./projects/"
+
+```bash
+./fission-python/create-project.sh my-api ./projects/
+```