docs: document grant request subcommands in README

[aaearon]

Summary

• Add grant request usage examples to the Usage section
• Add request entry to the Commands table
• Add grant request subcommands table (submit, list, get, cancel, approve, reject)
• Add grant request submit flags reference

Test plan

• Verify all subcommand descriptions match actual CLI help output
• Verify flag list for grant request submit is complete

[Copilot]

Pull request overview

Updates the project’s README to document the new grant request command group so users can discover and use the access-request approval workflow from the main CLI docs.

Changes:

• Adds grant request usage examples to the Usage section.
• Adds request to the Commands table and documents grant request subcommands (submit, list, get, cancel, approve, reject).
• Adds a flags reference section for grant request submit.

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[Copilot]

The grant request submit example looks like a fully flag-driven submission, but --role is display-only and the command still requires interactive role selection unless --role-id is provided. Also, in non-interactive mode submit requires --reason, --date, --timezone, --from, --to (and --role-id). Consider either updating the example to include --role-id + scheduling flags (and maybe --yes) or clarifying in the comment that it will prompt for missing fields in a TTY.

Suggested change

	grant request submit --provider azure --target "Prod" --role "Contributor" --reason "Incident"
	grant request submit --provider azure --target "Prod" --role "Contributor" --reason "Incident" # still prompts in a TTY for role selection/scheduling
	grant request submit --provider azure --target "Prod" --role-id "<role-id>" --reason "Incident" --date "2025-01-15" --timezone "America/New_York" --from "09:00" --to "17:00" --yes

[Copilot]

The subcommand arg placeholder/name is inconsistent with the actual CLI help. The Cobra Use strings are get [requestId], cancel [requestId], approve [requestId], reject [requestId] (and the long help refers to <requestId>). Consider standardizing the README to match the CLI (e.g., use [requestId] everywhere, or consistently use <requestId>), rather than mixing [id] with <id>.

Suggested change

	| `get [id]` | Show full request details; omit `<id>` in a TTY to open a fuzzy picker |
	| `cancel [id]` | Cancel an open request; omit `<id>` in a TTY to pick from your open requests |
	| `approve [id]` | Approve a pending request (approvers only); omit `<id>` in a TTY to pick from pending requests |
	| `reject [id]` | Reject a pending request (approvers only); omit `<id>` in a TTY to pick from pending requests |
	| `get [requestId]` | Show full request details; omit `[requestId]` in a TTY to open a fuzzy picker |
	| `cancel [requestId]` | Cancel an open request; omit `[requestId]` in a TTY to pick from your open requests |
	| `approve [requestId]` | Approve a pending request (approvers only); omit `[requestId]` in a TTY to pick from pending requests |
	| `reject [requestId]` | Reject a pending request (approvers only); omit `[requestId]` in a TTY to pick from pending requests |

[Copilot]

The grant request submit flags list is missing the short forms that the CLI exposes (--role, -r and --yes, -y). Aligning this list with the actual submit command flags will make it easier to copy/paste from the README.

Suggested change

	`--provider, -p` | `--target, -t` | `--role` | `--role-id` | `--reason` | `--priority` | `--date` | `--timezone` | `--from` | `--to` | `--yes` | `--refresh`
	`--provider, -p` | `--target, -t` | `--role, -r` | `--role-id` | `--reason` | `--priority` | `--date` | `--timezone` | `--from` | `--to` | `--yes, -y` | `--refresh`