Session ignores settings.json model pin (opus[1m]) and silently falls back to Fable; /model doesn't stick over Remote Control

Environment

• Claude Code version: 2.1.201
• Platform: Windows 10 Home (10.0.19045)
• Session driven via Remote Control (claude.ai)

What happened

• ~/.claude/settings.json contains "model": "opus[1m]" (no ANTHROPIC_MODEL env var, no project-level model override, no --model flag).
• The session nonetheless runs on claude-fable-5, and repeated attempts to switch the model during the session (asking the agent, and /model from the Remote Control client) do not take effect — the session keeps defaulting back to Fable.
• During the same session, tool calls intermittently failed with: claude-opus-4-8[1m] is temporarily unavailable, so auto mode cannot determine the safety of Bash right now (3+ occurrences over several hours) — suggesting Opus-tier availability problems may be triggering a silent model fallback that then persists for the session.

Expected

• The settings.json model pin should be honored at session start, or the fallback to a different model should be surfaced loudly and re-attempted, not silently persisted.
• /model should work (or clearly report unsupported) over Remote Control.

Additional friction

• /bug and /feedback respond with "isn't available over Remote Control", so this had to be filed via GitHub manually.

Repro sketch

1. Set "model": "opus[1m]" in ~/.claude/settings.json.
2. Start a session and drive it via Remote Control, ideally during an Opus availability blip.
3. Observe the session model (system context reports Fable) and try /model to switch — it reverts/defaults back.