docs(prompts): update context marker documentation format

Standardize the context marker section across all SDD workflow prompts.
Changed section title from "Context Verification Marker" to "Context Marker"
and updated the documentation to explain the multi-marker stacking pattern
with a clear format example.

Changes apply to:
- generate-spec.md
- generate-task-list-from-spec.md
- manage-tasks.md
- validate-spec-implementation.md

Author: ryderstorm

prompts/generate-spec.md

@@ -12,9 +12,13 @@ meta:
 
 # Generate Specification
 
-## Context Verification Marker
+## Context Marker
 
-**ALWAYS** begin replies with this starting character sequence: `SDD1️⃣`
+Always begin your response with all active emoji markers, in the order they were introduced.
+
+Format:  "<marker1><marker2><marker3>\n<response>"
+
+The marker for this instruction is:  SDD1️⃣
 
 ## You are here in the workflow
 

prompts/generate-task-list-from-spec.md

@@ -12,9 +12,13 @@ meta:
 
 # Generate Task List From Spec
 
-## Context Verification Marker
+## Context Marker
 
-**ALWAYS** begin replies with this starting character sequence: `SDD2️⃣`
+Always begin your response with all active emoji markers, in the order they were introduced.
+
+Format:  "<marker1><marker2><marker3>\n<response>"
+
+The marker for this instruction is:  SDD2️⃣
 
 ## You are here in the workflow
 

prompts/manage-tasks.md

@@ -12,9 +12,13 @@ meta:
 
 # Manage Tasks
 
-## Context Verification Marker
+## Context Marker
 
-**ALWAYS** begin replies with this starting character sequence: `SDD3️⃣`
+Always begin your response with all active emoji markers, in the order they were introduced.
+
+Format:  "<marker1><marker2><marker3>\n<response>"
+
+The marker for this instruction is:  SDD3️⃣
 
 ## You are here in the workflow
 

prompts/validate-spec-implementation.md

@@ -13,9 +13,13 @@ meta:
 
 # Validate Spec Implementation
 
-## Context Verification Marker
+## Context Marker
 
-**ALWAYS** begin replies with this starting character sequence: `SDD4️⃣`
+Always begin your response with all active emoji markers, in the order they were introduced.
+
+Format:  "<marker1><marker2><marker3>\n<response>"
+
+The marker for this instruction is:  SDD4️⃣
 
 ## You are here in the workflow