# Wiki List Columns Implementation Plan

> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.

**Goal:** Add a template-driven topdata wiki option for splitting provider-backed lists into configured columns with a fixed item count and optional forced empty columns.

**Architecture:** The toolkit wiki renderer gains a generic `columns` data-provider source that wraps another provider and exposes one row per rendered column. Each column row exposes `Items`, `Index`, and count metadata so page templates own markup while YAML owns row selection and chunking behavior. The module class page uses this provider for `ClassSkills`.

**Tech Stack:** Go `sow-toolkit`, YAML topdata wiki config, local HTML templates, Go tests.

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### Task 1: Renderer Provider

**Files:**
- Modify: `toolkit/internal/topdata/wiki_data_providers.go`
- Modify: `toolkit/internal/topdata/wiki_template.go`
- Test: `toolkit/internal/topdata/wiki_native_test.go`

- [ ] Write failing tests for a `columns` provider that chunks `ClassSkills` into rows with nested `Items`, including forced empty columns.
- [ ] Run `go test ./internal/topdata -run 'TestWikiTemplate.*Column|TestBuildNativeWikiRendersClassSkillColumns'` and confirm the new assertions fail because `columns` is not supported.
- [ ] Add `provider`, `columns`, `items_per_column`, and `force_columns` fields to `wikiDataProviderDefinition`.
- [ ] Validate that `columns` providers name an existing provider, use positive integer `columns` and `items_per_column`, and do not point at themselves.
- [ ] Allow nested `{{#each Items}}` loops by teaching template `#each` to iterate an array field from the current row before falling back to named providers.
- [ ] Implement deterministic chunking: each column receives up to `items_per_column`; extra source items continue into additional overflow columns; `force_columns: true` emits empty configured columns when there are fewer items.

### Task 2: Module Template

**Files:**
- Modify: `module/topdata/wiki/data.yaml`
- Modify: `module/topdata/wiki/templates/pages/classes.html`
- Modify: `module/topdata/wiki/README.md`

- [ ] Add `ClassSkillColumns` using `source: columns`, `provider: ClassSkills`, `columns: 3`, `items_per_column: 12`, and `force_columns: true`.
- [ ] Replace the flat class skill `<ul>` with a `.wiki-list-columns .wiki-list-columns--3` wrapper and nested `{{#each Items}}` loops.
- [ ] Document the generic `columns` provider fields for template authors.

### Task 3: Verification

**Files:**
- Verify: `toolkit/internal/topdata/...`
- Verify: `module/topdata/wiki/...`

- [ ] Run `go test ./internal/topdata -run 'TestWikiTemplate|TestBuildNativeWiki'`.
- [ ] Run `./build-tool.sh` from `toolkit/`.
- [ ] Run `SOW_TOOLS_DEV_BINARY=../toolkit/tools/sow-toolkit ./build-wiki.sh --force` from `module/`.
- [ ] Inspect generated class HTML for `wiki-list-columns--3`, three configured class-skill lists for shorter classes, and overflow columns for long lists.