feat: add /settings command and document /history for UI-command parity

- Add /settings command handler with inline settings keyboard
- Add /history to README commands table
- Update /help command list
- Remove unused Leagu.go old reference

README.md

@@ -94,6 +94,7 @@ Categorize your work sessions (e.g., Remote, Onsite, Meeting). The current work
 | Command                     | Action                                                      |
 | --------------------------- | ----------------------------------------------------------- |
 | `/start`                    | Show inline menu                                            |
+| `/settings`                 | Open settings menu                                          |
 | `/clockin`                  | Record clock-in                                             |
 | `/clockout`                 | Record clock-out                                            |
 | `/worktype`                 | Change current work type                                    |
@@ -101,6 +102,7 @@ Categorize your work sessions (e.g., Remote, Onsite, Meeting). The current work
 | `/dayoff`                   | Toggle today as day off                                     |
 | `/export [YYYY-MM]`         | Export monthly report (optional `YYYY-MM` in your calendar) |
 | `/summary [YYYY-MM]`        | Show monthly summary (optional `YYYY-MM`)                   |
+| `/history`                  | View calendar history (inline menu also)                    |
 | `/edit YYYY-MM-DD`          | View/edit events for a specific date                        |
 | `/note [DATE] HH:MM <text>` | Set note for an event at a specific time                    |
 | `/settimezone <IANA>`       | Set timezone (e.g. `Asia/Tehran`)                           |