Preserve model preference across team catalog refreshes

[warp-agent-staging]

Description

Preserves a shared Agent profile's saved base model and context limit when another team's catalog marks that model AdminDisabled. Runtime model lookup now resolves against the active team: teams that allow the saved model continue using it, while teams that disable it fall back to their usable Auto model without persisting that fallback. Admin-disabled models remain visible as disabled in the active team's picker.

Durable cleanup remains unchanged for globally Unavailable models and non-BYOK RequiresUpgrade models. This avoids a profile-schema migration and confines the exception to team-admin policy.

Linked Issue

QUALITY-2121 · Origin Slack thread

• The linked work item is a Linear bug labeled factory:wilson, Model Choice, and Bugs; it does not use GitHub's ready-to-implement label.
• Automated-tests-only verification was explicitly requested, so this PR has no screenshots or video.

Testing

• cargo nextest run --manifest-path /workspace/warp/Cargo.toml -p warp -E 'test(ai::llms::tests)' — 36 passed, 6618 skipped.

• cargo clippy --manifest-path /workspace/warp/Cargo.toml -p warp --all-targets --tests -- -D warnings — passed.

• /workspace/warp/script/format — completed successfully.

• I have manually tested my changes locally with ./script/run — not run because the requester chose automated tests only.

Agent Mode

• Warp Agent Mode - This PR was created via Warp's AI Agent Mode

CHANGELOG-BUG-FIX: Preserve saved Agent profile model preferences when another team disables the model.

[warp-agent-staging]

This PR was generated with Warp.

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