feat(plugins): implement Sprint 4 commands (#241-#258)

Sprint 4 - Plugin Commands implementation adding 18 new user-facing
commands across 8 plugins as part of V5.2.0 Plugin Enhancements.

**projman:**
- #241: /sprint-diagram - Mermaid visualization of sprint issues

**pr-review:**
- #242: Confidence threshold config (PR_REVIEW_CONFIDENCE_THRESHOLD)
- #243: /pr-diff - Formatted diff with inline review comments

**data-platform:**
- #244: /data-quality - DataFrame quality checks (nulls, duplicates, outliers)
- #245: /lineage-viz - dbt lineage as Mermaid diagrams
- #246: /dbt-test - Formatted dbt test runner

**viz-platform:**
- #247: /chart-export - Export charts to PNG/SVG/PDF via kaleido
- #248: /accessibility-check - Color blind validation (WCAG contrast)
- #249: /breakpoints - Responsive layout configuration

**contract-validator:**
- #250: /dependency-graph - Plugin dependency visualization

**doc-guardian:**
- #251: /changelog-gen - Generate changelog from conventional commits
- #252: /doc-coverage - Documentation coverage metrics
- #253: /stale-docs - Flag outdated documentation

**claude-config-maintainer:**
- #254: /config-diff - Track CLAUDE.md changes over time
- #255: /config-lint - 31 lint rules for CLAUDE.md best practices

**cmdb-assistant:**
- #256: /cmdb-topology - Infrastructure topology diagrams
- #257: /change-audit - NetBox audit trail queries
- #258: /ip-conflicts - Detect IP conflicts and overlaps

Closes #241, #242, #243, #244, #245, #246, #247, #248, #249,
#250, #251, #252, #253, #254, #255, #256, #257, #258

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/data-platform/commands/lineage-viz.md

@@ -0,0 +1,125 @@
+# /lineage-viz - Mermaid Lineage Visualization
+
+Generate Mermaid flowchart syntax for dbt model lineage.
+
+## Usage
+
+```
+/lineage-viz <model_name> [--direction TB|LR] [--depth N]
+```
+
+## Workflow
+
+1. **Get lineage data**:
+   - Use `dbt_lineage` to fetch model dependencies
+   - Capture upstream sources and downstream consumers
+
+2. **Build Mermaid graph**:
+   - Create nodes for each model/source
+   - Style nodes by materialization type
+   - Add directional arrows for dependencies
+
+3. **Output**:
+   - Render Mermaid flowchart syntax
+   - Include copy-paste ready code block
+
+## Output Format
+
+```mermaid
+flowchart LR
+    subgraph Sources
+        raw_customers[(raw_customers)]
+        raw_orders[(raw_orders)]
+    end
+
+    subgraph Staging
+        stg_customers[stg_customers]
+        stg_orders[stg_orders]
+    end
+
+    subgraph Marts
+        dim_customers{{dim_customers}}
+        fct_orders{{fct_orders}}
+    end
+
+    raw_customers --> stg_customers
+    raw_orders --> stg_orders
+    stg_customers --> dim_customers
+    stg_orders --> fct_orders
+    dim_customers --> fct_orders
+```
+
+## Node Styles
+
+| Materialization | Mermaid Shape | Example |
+|-----------------|---------------|---------|
+| source | Cylinder `[( )]` | `raw_data[(raw_data)]` |
+| view | Rectangle `[ ]` | `stg_model[stg_model]` |
+| table | Double braces `{{ }}` | `dim_model{{dim_model}}` |
+| incremental | Hexagon `{{ }}` | `fct_model{{fct_model}}` |
+| ephemeral | Dashed `[/ /]` | `tmp_model[/tmp_model/]` |
+
+## Options
+
+| Flag | Description |
+|------|-------------|
+| `--direction TB` | Top-to-bottom layout (default: LR = left-to-right) |
+| `--depth N` | Limit lineage depth (default: unlimited) |
+
+## Examples
+
+```
+/lineage-viz dim_customers
+/lineage-viz fct_orders --direction TB
+/lineage-viz rpt_revenue --depth 2
+```
+
+## Usage Tips
+
+1. **Paste in documentation**: Copy the output directly into README.md or docs
+2. **GitHub/GitLab rendering**: Both platforms render Mermaid natively
+3. **Mermaid Live Editor**: Paste at https://mermaid.live for interactive editing
+
+## Example Output
+
+For `/lineage-viz fct_orders`:
+
+~~~markdown
+```mermaid
+flowchart LR
+    %% Sources
+    raw_customers[(raw_customers)]
+    raw_orders[(raw_orders)]
+    raw_products[(raw_products)]
+
+    %% Staging
+    stg_customers[stg_customers]
+    stg_orders[stg_orders]
+    stg_products[stg_products]
+
+    %% Marts
+    dim_customers{{dim_customers}}
+    dim_products{{dim_products}}
+    fct_orders{{fct_orders}}
+
+    %% Dependencies
+    raw_customers --> stg_customers
+    raw_orders --> stg_orders
+    raw_products --> stg_products
+    stg_customers --> dim_customers
+    stg_products --> dim_products
+    stg_orders --> fct_orders
+    dim_customers --> fct_orders
+    dim_products --> fct_orders
+
+    %% Highlight target model
+    style fct_orders fill:#f96,stroke:#333,stroke-width:2px
+```
+~~~
+
+## Available Tools
+
+Use these MCP tools:
+- `dbt_lineage` - Get model dependencies (REQUIRED)
+- `dbt_ls` - List dbt resources
+- `dbt_docs_generate` - Generate full manifest if needed