fix(entry-skills): every handoff arm says to invoke the skill

skills/workflow-investigation-entry/references/invoke-skill.md

@@ -35,6 +35,8 @@ Bug context:
 
 #### If source is `continue`
 
+Invoke the **workflow-investigation-process** skill (Skill tool) with the next fenced block as its arguments. Do not act on the gathered context until its instructions load — the skill defines the process.
+
 ```
 Investigation session for: {work_unit}
 

skills/workflow-planning-entry/references/invoke-skill.md

@@ -25,6 +25,8 @@ Cross-cutting references: {list of applicable cross-cutting specs with brief sum
 
 #### If continuing or reviewing existing plan
 
+Invoke the **workflow-planning-process** skill (Skill tool) with the next fenced block as its arguments. Do not act on the gathered context until its instructions load — the skill defines the process.
+
 ```
 Planning session for: {topic}
 Work unit: {work_unit}

skills/workflow-specification-entry/references/invoke-skill.md

@@ -26,6 +26,8 @@ Action: {verb} specification
 
 #### If `work_type` is `bugfix`
 
+Invoke the **workflow-specification-process** skill (Skill tool) with the next fenced block as its arguments. Do not act on the gathered context until its instructions load — the skill defines the process.
+
 ```
 Specification session for: {work_unit}
 
@@ -59,6 +61,8 @@ Action: {verb} specification
 
 Check for completed research: `node .claude/skills/workflow-engine/scripts/engine.cjs manifest get {work_unit}.research.{topic} status`. Include the `Research:` line only when the status is `completed`; omit it otherwise.
 
+Invoke the **workflow-specification-process** skill (Skill tool) with the next fenced block as its arguments. Do not act on the gathered context until its instructions load — the skill defines the process.
+
 ```
 Specification session for: {work_unit}