refactor(shared): improve error handling with structured error types

[johnleider]

Summary

Improves developer experience by providing actionable error messages instead of generic failures. Users now see:

• What failed - specific operation (template download, feature application, etc.)
• Why it failed - root cause from the underlying error
• How to fix it - context-aware suggestions based on failure mode

Error Types Added

Error Type	When Thrown	Example Suggestion
TemplateDownloadError	Network/fetch failures	"Check your network connection and try again."
TemplateCopyError	Local template copy fails	"Check that you have read permissions for the template directory."
FeatureApplyError	Feature config fails	"Try creating the project without this feature and adding it manually."
DependencyInstallError	npm/pnpm install fails	"Try running 'pnpm install' manually in the project directory."
FileParseError	Analyze can't parse file	"The file may contain syntax errors. Fix them and try again."
DirectoryNotFoundError	Target dir doesn't exist	"Verify the path is correct and the directory exists."

Analyze Command Improvements

Files that fail to parse are now:

• Tracked and included in the report (parseErrors field)
• Displayed in console output (up to 10 files with reasons)
• Available for JSON reporter consumers

Before:

Failed to create project: Error: ENOENT: no such file or directory

After:

Failed to copy template from "/path/to/template": ENOENT: no such file or directory
  Suggestion: Verify the template path exists and is accessible.

Test plan

• Build passes (pnpm build)
• Lint passes (pre-existing catalog item warning unrelated to changes)
• Manual test: trigger template download error (disconnect network)
• Manual test: trigger feature apply error (malformed template)
• Manual test: run analyze on project with syntax errors