refactor(coding-agent): restructured XML tags to kebab-case format

- Renamed XML tags from underscore to kebab-case format for consistency across prompts and system messages.
- Updated context tag from `swarm_context` to `context` in render logic and test assertions.
- Consolidated conditional logic in subagent user prompt by removing duplicate assignment blocks.
- Updated system prompt documentation to reflect kebab-case naming convention for XML tags.

.omp/skills/system-prompts/SKILL.md

@@ -57,7 +57,7 @@ Tags encode enforcement level. Use consistently throughout:
 ### Special Tags
 
 ```
-<north_star>     Core values, ultimate objectives
+<north-star>     Core values, ultimate objectives
 <stance>         Communication style, attitude
 <commitment>     What the agent commits to doing
 <field>          Domain-specific mindset/context
@@ -242,9 +242,9 @@ External proof: tests, linters, type checks.
 3. State intent before each tool call
 </procedure>
 
-<north_star>
+<north-star>
 Core values. What ultimately matters.
-</north_star>
+</north-star>
 
 <prohibited>
 Actions that cause harm.
@@ -616,7 +616,7 @@ Structure:    <role> <context> <procedure> <directives> <parameters> <output>
 Capability:   <strengths> <tools> <operations>
 Examples:     <example name="kebab-case-name">
 Data:         <environment> <data> <documents>
-Special:      <north_star> <stance> <commitment> <field> <protocol>
+Special:      <north-star> <stance> <commitment> <field> <protocol>
 ```
 
 ### Example Name Patterns

packages/coding-agent/CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## [Unreleased]
+
 ### Added
 
 - Added `notes://` protocol for session-scoped scratch space to store large intermediate artifacts, subagent handoffs, and reusable planning notes
@@ -10,6 +11,8 @@
 
 ### Changed
 
+- Changed XML tag from `<swarm-context>` to `<context>` in subagent prompts and task rendering
+- Changed system reminder XML tags from underscore to kebab-case format (`<system-reminder>`)
 - Changed plan storage from `plan://` protocol to `notes://PLAN.md` for draft plans and `notes://<title>.md` for finalized approved plans
 - Changed plan mode to use session artifacts directory for plan storage instead of separate plans directory
 - Updated system prompt to document `notes://` protocol and internal URL expansion behavior

packages/coding-agent/src/prompts/system/subagent-user-prompt.md

@@ -1,8 +1,8 @@
 {{#if context}}
-<swarm-context>{{context}}</swarm-context>
+<context>
+{{context}}
+</context>
+{{/if}}
 
 # Your Assignment
-{{assignment}}
-{{else}}
-{{assignment}}
-{{/if}}
+{{assignment}}

packages/coding-agent/src/session/agent-session.ts

@@ -654,11 +654,11 @@ export class AgentSession {
 				if (toolName === "todo_write" && isError) {
 					const errorText = content?.find(part => part.type === "text")?.text;
 					const reminderText = [
-						"<system_reminder>",
+						"<system-reminder>",
 						"todo_write failed, so todo progress is not visible to the user.",
 						errorText ? `Failure: ${errorText}` : "Failure: todo_write returned an error.",
 						"Fix the todo payload and call todo_write again before continuing.",
-						"</system_reminder>",
+						"</system-reminder>",
 					].join("\n");
 					await this.sendCustomMessage(
 						{

packages/coding-agent/src/task/render.ts

@@ -366,9 +366,9 @@ function renderTaskSection(
 	const trimmed = task.trimEnd();
 	if (!expanded || !trimmed) return lines;
 
-	// Strip the shared <swarm_context>...</swarm_context> block — it's the same
+	// Strip the shared <context>...</context> block — it's the same
 	// across all tasks and just adds noise when expanded.
-	const stripped = trimmed.replace(/<swarm_context>[\s\S]*?<\/swarm_context>\s*/, "").trimStart();
+	const stripped = trimmed.replace(/<context>[\s\S]*?<\/context>\s*/, "").trimStart();
 	if (!stripped) return lines;
 
 	lines.push(`${continuePrefix}${theme.fg("dim", "Task")}`);

packages/coding-agent/test/tools/task-template.test.ts

@@ -20,7 +20,7 @@ describe("renderTemplate", () => {
 			assignment: "Full instructions for the agent.\nWith multiple lines.",
 		});
 		expect(result.task).toContain("Shared constraints here");
-		expect(result.task).toContain("<swarm_context>");
+		expect(result.task).toContain("<context>");
 		expect(result.task).toContain("Full instructions for the agent.\nWith multiple lines.");
 	});
 
@@ -30,7 +30,7 @@ describe("renderTemplate", () => {
 			description: "label",
 			assignment: "the real work",
 		});
-		expect(result.task).toStartWith("<swarm_context>context");
+		expect(result.task).toStartWith("<context>context");
 		expect(result.task).toContain("the real work");
 	});