Add agent change process (C0/C1/C2) and docs-mikado tool (#225)

## Summary
- Introduce C0/C1/C2 change classification based on the Mikado method, where documentation cards serve as persistent context for agents across sessions
- Add `docs-mikado` mise task to visualize active Mikado dependency chains from `status: active` and `requires` frontmatter fields
- Rename `zk-docs` task to `ai-docs`

## Changes
- **New:** `docs/how-to/agent-change-process.md` — methodology card
- **New:** `mise-tasks/docs-mikado` — Python uv script for dependency graph visualization
- **Renamed:** `mise-tasks/zk-docs` → `mise-tasks/ai-docs`
- **Updated:** `CLAUDE.md` — added Change Classification section, updated references
- **Updated:** `ai-assistance-guide.md`, `exploring-the-docs.md`, `how-to.md` — updated references and index

## Verification
- [x] `mise run ai-docs` works
- [x] `mise run docs-mikado` runs (no active chains yet, as expected)
- [x] `docs-check-links` — all valid
- [x] `docs-check-index` — all indexed
- [x] `docs-check-frontmatter` — all valid
- [x] All pre-commit hooks pass

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/225

docs/tutorials/ai-assistance-guide.md

@@ -17,12 +17,12 @@ This guide provides context for AI agents (like Claude Code) assisting with Blum
 These are non-negotiable for AI agents working in this repo:
 
 1. **Always use `--context=minikube-indri` with kubectl** - Work contexts exist that must never be touched
-2. **Run `mise run zk-docs` at session start** - Review current infrastructure state
+2. **Run `mise run ai-docs` at session start** - Review current infrastructure state
 3. **Never commit secrets** - The repo is public at github.com/eblume/blumeops
 4. **Wait for user review before deploying** - Create PRs, don't auto-deploy
 5. **Never merge PRs without explicit request** - The user merges after review
 
-Full rules are in the repo's `CLAUDE.md`.
+Full rules are in the repo's `CLAUDE.md`. See [[agent-change-process]] for the C0/C1/C2 change classification methodology.
 
 ## Workflow Conventions
 
@@ -84,7 +84,8 @@ BlumeOps operations are driven by mise tasks. Run `mise tasks` to list all avail
 
 | Task | When to Use |
 |------|-------------|
-| `zk-docs` | At session start - review infrastructure documentation |
+| `ai-docs` | At session start - review infrastructure documentation |
+| `docs-mikado` | View active Mikado dependency chains for C1/C2 changes |
 | `provision-indri` | Deploy changes to [[indri]]-hosted services via Ansible |
 | `services-check` | After deployments - verify all services are healthy |
 | `pr-comments` | Check unresolved PR comments during review |

docs/tutorials/exploring-the-docs.md

@@ -33,7 +33,7 @@ You probably want quick access to operational details:
 - [[plans]] captures migration and transition plans for future execution
 - [[reference]] has service URLs, commands, and config locations
 - [[ai-assistance-guide]] explains how to work effectively with Claude
-- Run `mise run zk-docs` to prime AI context with key documentation
+- Run `mise run ai-docs` to prime AI context with key documentation
 
 ### For Claude/AI Agents
 
@@ -77,10 +77,10 @@ Pre-commit hooks automatically validate that all wiki-links point to existing fi
 
 ## AI Context Priming
 
-The `zk-docs` mise task concatenates key documentation files for AI context:
+The `ai-docs` mise task concatenates key documentation files for AI context:
 
 ```bash
-mise run zk-docs -- --style=header --color=never --decorations=always
+mise run ai-docs -- --style=header --color=never --decorations=always
 ```
 
 This outputs the AI assistance guide, reference index, how-to index, architecture overview, and tutorials index - providing Claude with essential context for BlumeOps operations.