feat(copilot-cli): Phase 4 — Copilot CLI skill templates

Add 5 embedded skill templates for GitHub Copilot CLI integration:
  - ctx-status: context summary and health check
  - ctx-recall: session history browsing
  - ctx-drift: context drift detection
  - ctx-compact: archive completed tasks
  - ctx-next: advance to next task

Each skill is written to .github/skills/<name>/SKILL.md when
'ctx hook copilot-cli --write' is invoked. Skills use YAML
frontmatter (name, description) with Markdown instructions,
following the Copilot CLI skill format.

Wiring:
  - embed.go: glob for hooks/copilot-cli/skills/*/SKILL.md
  - agent.go: CopilotCLISkills() reader function
  - run.go: writeCopilotCLISkills() called from WriteCopilotCLIHooks()
  - asset.go: DirHooksCopilotCLISkills constant
  - hook.go: DirGitHubSkills, FileSKILLMd constants
  - text/hook.go: DescKeyWriteHookCopilotCLISkills key
Signed-off-by: ersan bilik <ersanbilik@gmail.com>

Author: bilersan

internal/assets/embed.go

@@ -14,6 +14,7 @@ import (
 //go:embed claude/skills/*/references/*.md claude/skills/*/SKILL.md
 //go:embed context/*.md project/* entry-templates/*.md hooks/*.md
 //go:embed hooks/copilot-cli/*.json hooks/copilot-cli/*.md hooks/copilot-cli/scripts/*.sh hooks/copilot-cli/scripts/*.ps1
+//go:embed hooks/copilot-cli/skills/*/SKILL.md
 //go:embed hooks/messages/*/*.txt hooks/messages/registry.yaml
 //go:embed prompt-templates/*.md ralph/*.md schema/*.json why/*.md
 //go:embed permissions/*.txt commands/*.yaml commands/text/*.yaml journal/*.css

internal/assets/hooks/copilot-cli/skills/ctx-compact/SKILL.md

@@ -0,0 +1,35 @@
+---
+name: ctx-compact
+description: "Archive completed tasks and trim context. Use when context files are growing large."
+---
+
+Archive completed tasks and trim stale context entries to keep
+the context directory lean and within token budgets.
+
+## When to Use
+
+- When TASKS.md has many completed items
+- When context token count is growing large
+- When asked to "clean up" or "compact" context
+- Before starting a new phase of work
+
+## When NOT to Use
+
+- When all tasks are still active
+- When context is already compact
+
+## Execution
+
+Run the compact operation:
+
+```bash
+ctx compact
+```
+
+This archives completed tasks from TASKS.md into the session
+history and trims stale entries from other context files.
+
+After running, confirm:
+- How many tasks were archived
+- Current token budget usage
+- Whether any manual cleanup is recommended

internal/assets/hooks/copilot-cli/skills/ctx-drift/SKILL.md

@@ -0,0 +1,41 @@
+---
+name: ctx-drift
+description: "Detect context drift. Use to find stale paths, broken references, and outdated context."
+---
+
+Detect context drift: stale paths, missing files, constitution
+violations, and semantic staleness in context files.
+
+## When to Use
+
+- At session start to verify context health
+- After refactors, renames, or major structural changes
+- When asked "is our context clean?" or "anything stale?"
+- Before a release or milestone
+
+## When NOT to Use
+
+- When you just ran ctx status and everything looked fine
+- Repeatedly without changes in between
+
+## Execution
+
+Run the structural drift check:
+
+```bash
+ctx drift
+```
+
+This catches dead paths, missing files, staleness indicators,
+and constitution violations.
+
+After running, also do a semantic check: read the context files
+and compare them to what you know about the codebase. Look for:
+
+- Outdated conventions that the code no longer follows
+- Decisions whose rationale no longer applies
+- Architecture descriptions that have changed
+- Learnings about bugs that were since fixed
+
+Report findings as actionable items, not raw output. Propose
+specific fixes for each issue found.

internal/assets/hooks/copilot-cli/skills/ctx-next/SKILL.md

@@ -0,0 +1,34 @@
+---
+name: ctx-next
+description: "Advance to the next task. Use when finishing a task or when asked what to work on next."
+---
+
+Mark the current task complete and advance to the next one in
+the context task list.
+
+## When to Use
+
+- After completing a task
+- When the user asks "what's next?"
+- When picking up work after a break
+
+## When NOT to Use
+
+- When the user has a specific task in mind already
+- When no tasks exist in the context
+
+## Execution
+
+Show the current task and mark it complete:
+
+```bash
+ctx next
+```
+
+This reads `.context/TASKS.md`, identifies the current in-progress
+task, marks it done, and shows the next pending task.
+
+After running, summarize:
+- What was completed
+- What the next task is
+- Any blockers or dependencies noted in the task list

internal/assets/hooks/copilot-cli/skills/ctx-recall/SKILL.md

@@ -0,0 +1,42 @@
+---
+name: ctx-recall
+description: "Browse session history. Use when referencing past discussions or finding context from previous work."
+---
+
+Browse, inspect, and export AI session history.
+
+## When to Use
+
+- When the user asks "what did we do last time?"
+- When looking for context from previous work sessions
+- When exporting sessions to the journal
+- When searching for a specific session by topic or date
+
+## When NOT to Use
+
+- When the user just wants current context (use ctx-status instead)
+- For modifying session content (recall is read-only)
+
+## Execution
+
+List recent sessions:
+
+```bash
+ctx recall list --limit 5
+```
+
+Show details of a specific session:
+
+```bash
+ctx recall show --latest
+ctx recall show <session-id>
+```
+
+Export sessions to journal markdown:
+
+```bash
+ctx recall export --all
+```
+
+After listing sessions, summarize relevant findings rather than
+dumping raw output.

internal/assets/hooks/copilot-cli/skills/ctx-status/SKILL.md

@@ -0,0 +1,42 @@
+---
+name: ctx-status
+description: "Show context summary and health. Use at session start or when unclear about project state."
+---
+
+Show the current context status: files, token budget, tasks, and
+recent activity.
+
+## When to Use
+
+- At session start to orient before doing work
+- When confused about what is being worked on
+- To check token usage and context health
+- When the user asks "what's the state of the project?"
+
+## When NOT to Use
+
+- When you already loaded context via `ctx agent` in this session
+- Repeatedly within the same session without changes in between
+
+## Execution
+
+```bash
+ctx status
+```
+
+For verbose output with file previews:
+
+```bash
+ctx status --verbose
+```
+
+For machine-readable output:
+
+```bash
+ctx status --json
+```
+
+After running, summarize the key points:
+- How many active tasks remain
+- Whether any context files are empty or stale
+- What was most recently modified

internal/assets/read/agent/agent.go

@@ -90,3 +90,31 @@ func CopilotCLIScripts() (map[string][]byte, error) {
 	}
 	return scripts, nil
 }
+
+// CopilotCLISkills reads all embedded Copilot CLI skill templates.
+// Returns a map of skill directory name to SKILL.md content for skills
+// in hooks/copilot-cli/skills/.
+//
+// Returns:
+//   - map[string][]byte: Skill name -> SKILL.md content
+//   - error: Non-nil if the directory read fails
+func CopilotCLISkills() (map[string][]byte, error) {
+	skills := make(map[string][]byte)
+	entries, dirErr := fs.ReadDir(assets.FS, asset.DirHooksCopilotCLISkills)
+	if dirErr != nil {
+		return nil, dirErr
+	}
+	for _, entry := range entries {
+		if !entry.IsDir() {
+			continue
+		}
+		name := entry.Name()
+		skillPath := asset.DirHooksCopilotCLISkills + "/" + name + "/" + asset.FileSKILLMd
+		content, readErr := assets.FS.ReadFile(skillPath)
+		if readErr != nil {
+			return nil, readErr
+		}
+		skills[name] = content
+	}
+	return skills, nil
+}

internal/cli/hook/cmd/root/run.go

@@ -235,6 +235,11 @@ func WriteCopilotCLIHooks(cmd *cobra.Command) error {
 		cmd.Println("  ⚠ mcp-config.json: " + err.Error())
 	}
 
+	// Write .github/skills/<name>/SKILL.md for Copilot CLI skills
+	if err := writeCopilotCLISkills(cmd); err != nil {
+		writeErr.WarnFile(cmd, cfgHook.DirGitHubSkills, err)
+	}
+
 	hook.InfoCopilotCLISummary(cmd)
 	return nil
 }
@@ -292,6 +297,35 @@ func writeCopilotCLIInstructions(cmd *cobra.Command) error {
 	return nil
 }
 
+// writeCopilotCLISkills creates .github/skills/<name>/SKILL.md for each
+// embedded Copilot CLI skill template. Skips skills that already exist.
+func writeCopilotCLISkills(cmd *cobra.Command) error {
+	skills, readErr := agent.CopilotCLISkills()
+	if readErr != nil {
+		return readErr
+	}
+
+	skillsBase := filepath.Join(cfgHook.DirGitHub, cfgHook.DirGitHubSkills)
+	for name, content := range skills {
+		skillDir := filepath.Join(skillsBase, name)
+		target := filepath.Join(skillDir, cfgHook.FileSKILLMd)
+
+		if _, err := os.Stat(target); err == nil {
+			hook.InfoCopilotCLICreated(cmd, target+" (exists, skipped)")
+			continue
+		}
+
+		if err := os.MkdirAll(skillDir, fs.PermExec); err != nil {
+			return err
+		}
+		if wErr := os.WriteFile(target, content, fs.PermFile); wErr != nil {
+			return wErr
+		}
+		hook.InfoCopilotCLICreated(cmd, target)
+	}
+	return nil
+}
+
 // WriteAgentsMd generates AGENTS.md in the project root.
 //
 // Creates AGENTS.md with universal agent instructions. Preserves existing

internal/config/asset/asset.go

@@ -10,24 +10,25 @@ import "path"
 
 // Embedded asset directory names.
 const (
-	DirClaude              = "claude"
-	DirClaudePlugin        = "claude/.claude-plugin"
-	DirClaudeSkills        = "claude/skills"
-	DirCommands            = "commands"
-	DirCommandsText        = "commands/text"
-	DirContext             = "context"
-	DirEntryTemplates      = "entry-templates"
-	DirHooks               = "hooks"
-	DirHooksCopilotCLI     = "hooks/copilot-cli"
-	DirHooksCopilotCLIScrp = "hooks/copilot-cli/scripts"
-	DirHooksMessages       = "hooks/messages"
-	DirJournal             = "journal"
-	DirPermissions         = "permissions"
-	DirProject             = "project"
-	DirPromptTemplates     = "prompt-templates"
-	DirRalph               = "ralph"
-	DirSchema              = "schema"
-	DirWhy                 = "why"
+	DirClaude                = "claude"
+	DirClaudePlugin          = "claude/.claude-plugin"
+	DirClaudeSkills          = "claude/skills"
+	DirCommands              = "commands"
+	DirCommandsText          = "commands/text"
+	DirContext               = "context"
+	DirEntryTemplates        = "entry-templates"
+	DirHooks                 = "hooks"
+	DirHooksCopilotCLI       = "hooks/copilot-cli"
+	DirHooksCopilotCLIScrp   = "hooks/copilot-cli/scripts"
+	DirHooksCopilotCLISkills = "hooks/copilot-cli/skills"
+	DirHooksMessages         = "hooks/messages"
+	DirJournal               = "journal"
+	DirPermissions           = "permissions"
+	DirProject               = "project"
+	DirPromptTemplates       = "prompt-templates"
+	DirRalph                 = "ralph"
+	DirSchema                = "schema"
+	DirWhy                   = "why"
 )
 
 // JSON field keys used when parsing embedded asset files.

internal/config/embed/text/hook.go

@@ -24,6 +24,7 @@ const (
 	DescKeyWriteHookAgentsSummary      = "write.hook-agents-summary"
 	DescKeyWriteHookCopilotCLICreated  = "write.hook-copilot-cli-created"
 	DescKeyWriteHookCopilotCLISkipped  = "write.hook-copilot-cli-skipped"
+	DescKeyWriteHookCopilotCLISkills   = "write.hook-copilot-cli-skills"
 	DescKeyWriteHookCopilotCLISummary  = "write.hook-copilot-cli-summary"
 	DescKeyWriteHookCopilotCreated     = "write.hook-copilot-created"
 	DescKeyWriteHookCopilotForceHint   = "write.hook-copilot-force-hint"