feat(v0.3): replace built-in task CLAUDE.md with v0.3 default content

Replaces the v0.2 task-scoped template with the v0.3 workspace
guidelines (file placement conventions + session handoff).
ClaudeMD signature is preserved for API compatibility; the
parameters are no longer interpolated.

internal/seed/templates.go

@@ -2,26 +2,29 @@ package seed
 
 import "fmt"
 
-// ClaudeMD returns the advisory CLAUDE.md content for a workspace.
+// ClaudeMD returns the built-in default CLAUDE.md content for a task workspace.
+// Parameters are accepted for API compatibility but are not interpolated in v0.3.
 func ClaudeMD(slug, category, workspacePath string) string {
-	return fmt.Sprintf(`# Task Workspace: %s
+	_ = slug
+	_ = category
+	_ = workspacePath
+	return `# Workspace Guidelines
 
-This is a ctask-managed workspace.
+This is a ctask workspace. Prefer operating inside this directory unless explicitly instructed otherwise.
 
-- **Category:** %s
-- **Workspace:** %s
+## File Placement
 
-## Scope
+- Source code and scripts -> workspace root or ` + "`src/`" + `
+- Documentation, summaries, reports -> ` + "`docs/`" + `
+- Deliverables and exports -> ` + "`output/`" + `
+- Reference material and imported files -> ` + "`context/`" + `
+- Do not place non-code outputs (docs, summaries, exports) in the workspace root
 
-This workspace is scoped to a single task. Keep work focused on the task described in notes.md.
+## Conventions
 
-## Files
-
-- task.yaml -- Task metadata (machine-managed, do not edit)
-- notes.md -- Task log (human/agent-managed)
-- context/ -- Reference documents (user-managed)
-- output/ -- Task deliverables and artifacts
-- logs/ -- Session logs (automatic session snapshots)
+- Do not install global packages or modify system files unless asked
+- Record important assumptions and actions in notes.md
+- Keep the workspace root clean -- use subdirectories for organization
 
 ## Session Handoff
 
@@ -32,12 +35,8 @@ Before ending a session, append a brief summary to notes.md with:
 - Open follow-ups or unfinished work
 - How to continue from here
 
-Keep it concise -- a few bullet points is enough. This helps the developer (or a future session) resume without losing context.
-
-## Repository and Package Identity
-
-Never invent remote repository, package, or module identities. Do not guess GitHub usernames/orgs, repo URLs, Go module paths, release install commands, or package manager coordinates. Only provide remote clone/install/publish commands if they are verified from the actual repo config (e.g. go.mod, git remote -v) or explicitly provided by the user. If publishing/release details are not configured, say so plainly and provide local-only build/install commands instead.
-`, slug, category, workspacePath)
+Keep it concise -- a few bullet points is enough.
+`
 }
 
 // NotesMD returns the skeleton notes.md content.