Add context packs impact analysis and message validation

specs/versions/0.1/commands.md

@@ -100,9 +100,55 @@ gsp flatten <id> [--root .] [--depth 3] [--include-type a,b] [--exclude-type a,b
 Create a compact AI context pack.
 
 ```bash
-gsp pack <id> [--root .] [--depth 3] [--budget 12000] [--out context-pack.json]
+gsp pack <id> [--root .] [--for implement] [--stage implement] [--depth 3] [--budget 12000] [--format json|md|canvas] [--out context-pack.json]
 ```
 
+The `--for` value describes the task intent:
+
+```text
+design
+implement
+review
+test
+acceptance
+handoff
+inspect
+```
+
+Formats:
+
+```text
+json      Machine-readable context pack.
+md        Human-readable and AI-readable context pack.
+canvas    Obsidian JSON Canvas for included GSP relations.
+```
+
+## impact
+
+Find direct and indirect GSPs affected by a GSP id.
+
+```bash
+gsp impact <id> [--root .] [--depth -1] [--format json|md|canvas] [--out impact.json]
+```
+
+Formats:
+
+```text
+json      Machine-readable impact result.
+md        Human-readable impact report.
+canvas    Obsidian JSON Canvas for affected relations.
+```
+
+## message
+
+Validate GSP agent communication messages.
+
+```bash
+gsp message validate <file> [--root .] [--out message-report.json]
+```
+
+Message files use YAML and reference GSP ids from the project.
+
 ## graph
 
 Generate a relation graph.