feat(cli): add /model slash command to show or set Claude model

[metowolf]

Summary

• Add a new /model slash command that allows users to view or switch the Claude model during a session.
• /model (no argument) — prints the currently active model (e.g. Claude model: claude-sonnet-4-6).
• /model <name> — switches the session to the given model (e.g. /model claude-opus-4-7).
• /model auto — resets the session to the default/auto model selection.

Changes

• cli/src/parsers/specialCommands.ts — Added parseModel() function and ModelCommandResult interface; wired into parseSpecialCommand() which now returns type: 'model' and the optional model string.
• cli/src/parsers/specialCommands.test.ts — Full unit-test coverage for parseModel and the /model cases in parseSpecialCommand.
• cli/src/claude/runClaude.ts — Handle specialCommand.type === 'model': show current model when no argument is supplied, or call setModel / pushKeepAlive when a model name is given.
• cli/src/modules/common/slashCommands.ts — Register /model in the built-in command list with a description so it appears in autocomplete / help.

Test plan

• Run vitest — all existing and new tests pass.
• Send /model in a session — response shows Claude model: <current>.
• Send /model claude-opus-4-7 — response shows Claude model set to claude-opus-4-7 and subsequent messages use that model.
• Send /model auto — resets to default model selection.
• Confirm that /modeler and other partial matches do not trigger the command.

[github-actions]

Findings

• No findings.

Summary

• Review mode: initial
• Reviewed the latest diff for the Claude /model parser, runner handling, slash-command registration, and parser tests. No high-confidence issues found in the modified lines.
• Residual risk/testing gap: handler side effects in cli/src/claude/runClaude.ts (setModel, pushKeepAlive, consumed local id, emitted status message) are not covered by a focused runner test; current added coverage is parser-level only.

Testing

• Not run (automation)

HAPI Bot

[tiann]

I don’t think this is a good idea. Codex / Claude Code have slash-command functionality because they are TUIs, whereas we are on the web, with buttons and dialogs, so there’s no need to use this kind of interaction.