refactor: rename command files for namespace consistency

BREAKING CHANGE: All generic command names now prefixed with plugin namespace.
See CHANGELOG.md v7.0.0 for complete rename map.

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

plugins/data-platform/commands/data-ingest.md

@@ -0,0 +1,45 @@
+# /ingest - Data Ingestion
+
+## Skills to Load
+- skills/mcp-tools-reference.md
+- skills/visual-header.md
+
+## Visual Output
+
+Display header: `DATA-PLATFORM - Ingest`
+
+## Usage
+
+```
+/ingest [source]
+```
+
+## Workflow
+
+1. **Identify source**:
+   - File path: determine format (CSV, Parquet, JSON)
+   - SQL query or table name: query PostgreSQL
+
+2. **Load data**:
+   - Files: `read_csv`, `read_parquet`, `read_json`
+   - Database: `pg_query`
+
+3. **Validate**: Check row count against 100k limit
+
+4. **Report**: data_ref, row count, columns, memory usage, preview
+
+## Examples
+
+```
+/ingest data/sales.csv
+/ingest data/customers.parquet
+/ingest "SELECT * FROM orders WHERE created_at > '2024-01-01'"
+```
+
+## Required MCP Tools
+
+- `read_csv` - Load CSV files
+- `read_parquet` - Load Parquet files
+- `read_json` - Load JSON/JSONL files
+- `pg_query` - Query PostgreSQL database
+- `list_data` - List loaded DataFrames