[FEATURE] Expose effort level control to Remote Control sessions

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When controlling a Claude Code session from Remote Control (claude.ai/code web, mobile, etc.), there's no way to change the reasoning effort level. /effort is not a supported slash command in the remote UI — the CLI explicitly responds that it can't be changed remotely, since /effort is a local-TUI picker that requires Ink/React rendering in the terminal.

Related parent issue #28351 addresses slash commands over remote control broadly, but the known implementation (per reverse-engineered comment in #28351) scopes to prompt-type and allowlist-only local-jsx commands. Interactive TUI-picker commands — /model, /config, /memory, and by extension /effort — are explicitly excluded because they need the local terminal to render. So even if #28351 ships, effort level cannot be changed from Remote Control.

Proposed Solution

Expose effort level to Remote Control through one of:

1. Non-interactive /effort <level> variant — accept the level as an argument (/effort high, /effort max) instead of launching the TUI picker. Bypasses local rendering and fits the tengu_bridge_slash_commands allowlist mechanism.
2. Remote-client effort picker UI — add an effort selector in claude.ai/code and mobile clients, separate from the slash command system.
3. Settings-based programmatic control — wire effortLevel in settings.json (per #34171) so it can be toggled remotely.

Option 1 is the smallest surface area.

Alternative Solutions

• Return to the laptop to flip effort via local /effort — current workaround, negates the point of Remote Control.
• Start the session at Max and pay the token cost for the whole run — wasteful.
• Kill the remote session and restart at the desired effort — loses context.

Priority

Medium - Would be very helpful

Feature Category

Performance and speed

Use Case Example

Remote user starts a session at Medium effort to investigate a bug from their phone. Investigation reveals the bug is deeper than expected and needs Max-effort reasoning. User is away from their laptop. No way to escalate effort without physically returning to the terminal. Either downgrade productivity or waste tokens pre-emptively setting Max.

Additional Context

Related issues:

• #28351 — Allow slash command usage over remote-control (parent, 57 👍, active). Known implementation scope excludes TUI-picker commands; /effort falls in that category.
• #28379 — Slash commands not supported in /remote-control UI (duplicate of #28351).
• #34171 — Allow persisting thinking effort level across sessions (11 👍, active). Adjacent — if effortLevel in settings.json were honored, remote control could change effort via settings write.
• #37441 — Web app needs user-facing reasoning effort control (closed as invalid by auto-bot on 2026-03-25, appears to be a misfire — issue body is clearly about Claude Code's web app).
• #51059 — Per-model effort level configuration (2026-04-20).