fix(#2697): replace retired /gsd: prefix with /gsd- in all user-facing text (#2699)

All workflow, command, reference, template, and tool-output files that
surfaced /gsd:<cmd> as a user-typed slash command have been updated to
use /gsd-<cmd>, matching the Claude Code skill directory name.

Closes #2697

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

commands/gsd/graphify.md

@@ -43,7 +43,7 @@ Knowledge graph is disabled. To activate:
 
   node $HOME/.claude/get-shit-done/bin/gsd-tools.cjs config-set graphify.enabled true
 
-Then run /gsd:graphify build to create the initial graph.
+Then run /gsd-graphify build to create the initial graph.
 ```
 
 ---
@@ -65,7 +65,7 @@ Parse `$ARGUMENTS` to determine the operation mode:
 ```
 GSD > GRAPHIFY
 
-Usage: /gsd:graphify <mode>
+Usage: /gsd-graphify <mode>
 
 Modes:
   build           Build or rebuild the knowledge graph
@@ -85,7 +85,7 @@ node $HOME/.claude/get-shit-done/bin/gsd-tools.cjs graphify query <term>
 Parse the JSON output and display results:
 - If the output contains `"disabled": true`, display the disabled message from Step 1 and **STOP**
 - If the output contains `"error"` field, display the error message and **STOP**
-- If no nodes found, display: `No graph matches for '<term>'. Try /gsd:graphify build to create or rebuild the graph.`
+- If no nodes found, display: `No graph matches for '<term>'. Try /gsd-graphify build to create or rebuild the graph.`
 - Otherwise, display matched nodes grouped by type, with edge relationships and confidence tiers (EXTRACTED/INFERRED/AMBIGUOUS)
 
 **STOP** after displaying results. Do not spawn an agent.