Better error messages and status outputs

[httpdss]

Summary
Improve clarity and consistency of logs and user-facing messages.

Proposed changes

• Harmonize created/updated/skipped/backed up/renamed messages and include file paths.
• Final run summary with counts per action.
• mcp_server.get_structure_info to render folders/files cleanly (avoid raw dicts).
• Standardize emojis/symbols across CLI output for readability.

Files

• struct_module/commands/generate.py
• struct_module/file_item.py
• struct_module/mcp_server.py
• docs/usage.md (new screenshots/GIFs)

Acceptance criteria

• Output is consistent and easy to scan; final summary present.
• get_structure_info produces clean listings.
• Tests adjusted to new messages where applicable.