claude --continue does not preserve the original session's --model

Bug

When a session is created with --model <X>, resuming it with claude --continue uses the current default model (from settings) instead of preserving the original session's model.

Repro

# Settings default is sonnet
echo "What model are you?" | claude -p --model haiku
# Responds correctly as Haiku 4.5

claude --continue
# Status bar shows Sonnet 4.6 — the default, not haiku
# Model self-identifies as Haiku (from preserved system prompt) but is actually running as Sonnet

Expected

claude --continue should resume using the same model (haiku) that was specified via --model when the session was created.

Actual

claude --continue ignores the original --model and uses the current default model from settings.

Impact

• Misleading when inspecting previous sessions (appears to be a different model than what actually ran)
• If a user created a session with a specific model for cost/capability reasons, continuing it silently switches models

Environment

• Claude Code v2.1.71
• Windows (MSYS2/bash)