Add Mistral Vibe support for Agency agents (#658)

* Add Mistral Vibe support for Agency agents

- Add Mistral Vibe entry to tools.json with proper configuration
  (id, label, kebab, format, installKind, dest, detection, version)
- Implement convert_vibe() function in convert.sh for Mistral Vibe's format
  - Generates TOML agent configuration files (~/.vibe/agents/<slug>.toml)
  - Generates markdown prompt files (~/.vibe/prompts/<slug>.md)
  - Each agent gets agent_type and system_prompt_id (no hardcoded active_model)
- Add install_vibe() function in install.sh with full feature support
  - Copies both agent TOML and prompt MD files
  - Supports division/agent filtering and environment variable overrides
  - Uses VIBE_HOME environment variable for custom install paths
- Add Mistral Vibe detection and tool labeling
- Add Mistral Vibe to all necessary case statements and arrays
- Update README.md to document Mistral Vibe support
- All changes validated with scripts/check-tools.sh

Mistral Vibe uses a two-file approach per agent:
- ~/.vibe/agents/<slug>.toml for agent configuration
- ~/.vibe/prompts/<slug>.md for system prompts

Users can specify active_model in their agent TOML files or rely on their
Vibe configuration default model.

Usage: ./scripts/install.sh --tool vibe [--division X] [--agent Y]

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

* Address PR #658 review feedback: add .gitignore, README, and fix icon

- Add integrations/vibe/README.md documenting the Mistral Vibe integration
- Update .gitignore to ignore integrations/vibe/agents/ and prompts/
- Update convert.sh usage() to include vibe in the tool list
- Fix tools.json: change vibe icon from 'mistral' to null (no mistral.svg)
- Bonus: update vibe accent color from #FF69B4 to #FA520F (Mistral brand orange)

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

---------

Co-authored-by: Mistral Vibe <vibe@mistral.ai>

integrations/vibe/README.md

@@ -0,0 +1,116 @@
+# Mistral Vibe Integration
+
+Mistral Vibe uses two files per agent:
+- A TOML configuration file (`~/.vibe/agents/<slug>.toml`)
+- A Markdown prompt file (`~/.vibe/prompts/<slug>.md`)
+
+The generated files come from `scripts/convert.sh --tool vibe`, which writes
+one TOML agent configuration and one Markdown prompt file per agency agent
+into `integrations/vibe/agents/` and `integrations/vibe/prompts/` respectively.
+
+## Generate
+
+From the repository root:
+
+```bash
+./scripts/convert.sh --tool vibe
+```
+
+## Install
+
+Run the installer from your target directory:
+
+```bash
+cd /your/project && /path/to/agency-agents/scripts/install.sh --tool vibe
+```
+
+This copies the generated files into:
+
+```text
+~/.vibe/agents/<slug>.toml
+~/.vibe/prompts/<slug>.md
+```
+
+You can override the destination using the `VIBE_HOME` environment variable:
+
+```bash
+VIBE_HOME=~/.config/vibe ./scripts/install.sh --tool vibe
+```
+
+## Generated Format
+
+Each generated agent pair lives in:
+
+```text
+integrations/vibe/agents/<slug>.toml
+integrations/vibe/prompts/<slug>.md
+```
+
+### Agent TOML File
+
+The minimal Vibe agent configuration:
+
+```toml
+agent_type = "agent"
+system_prompt_id = "<slug>"
+```
+
+Users can specify `active_model` in their agent TOML files or rely on their
+Vibe configuration default model.
+
+### Prompt Markdown File
+
+The prompt file contains:
+- A title header with the agent name
+- The agent description
+- The full Markdown body from the source agent
+
+## Usage
+
+After installation, reference agents in Mistral Vibe by their system prompt ID
+(which matches the filename slug).
+
+Example:
+```text
+Use the Code Reviewer agent to analyze this pull request.
+```
+
+## Filtering
+
+Install only specific divisions or agents:
+
+```bash
+# Install only agents from Division 1
+./scripts/install.sh --tool vibe --division 1
+
+# Install only the code-reviewer agent
+./scripts/install.sh --tool vibe --agent code-reviewer
+```
+
+## Regenerate
+
+After modifying source agents:
+
+```bash
+./scripts/convert.sh --tool vibe
+./scripts/install.sh --tool vibe
+```
+
+## Troubleshooting
+
+### Mistral Vibe not detected
+
+Make sure `vibe` is in your PATH, or that `~/.vibe/` already exists:
+
+```bash
+which vibe
+vibe --version
+```
+
+### Integration files not generated
+
+Generate the Vibe artifacts before installing:
+
+```bash
+./scripts/convert.sh --tool vibe
+```