docs(code-review): steer model selection to review_depth presets

[factory-nizar]

Part of AUT-2375

Why

Many Droid code review workflows pin a specific model through review_model, so they stay on old models (about a fifth of reviews still run on GPT-5.2). The review presets are about to track Factory's recommended models automatically (Factory-AI/droid-action#144, backed by the tier aliases in Factory-AI/factory-mono#22502). The docs should push people toward the presets and away from pinning models.

What

• Code review guide: the Review depth section presents review_depth (deep / shallow) as the only model setting most teams need, explains that presets follow Factory's recommended model, notes that deep is what the Factory team uses (a hand-picked, strong balanced model with high reasoning), and tells users with older setups to remove review_model, security_model, and reasoning_effort. A new "Advanced: model overrides" subsection, opened by a warning that most teams should skip it, documents the override inputs, lists provider tier aliases (openai-, anthropic-, oss-latest-premium/balanced/fast), with openai-latest-premium / anthropic-latest-balanced as the example, and discourages exact model IDs.
• Removed the outdated "Change the model" section, which showed droid exec --model claude-sonnet-4-5-20250929 and does not match how droid-action workflows are configured.
• In the "All workflow inputs" table, review_model and reasoning_effort are labeled "Advanced" and link to the overrides subsection.
• Security review page: security_model is labeled "Advanced", notes that PR security reviews follow review_depth when it is empty, and links to the overrides subsection.

Japanese pages are left to the sync-jp-docs workflow.

Rollout

Merge together with (or after) the droid-action release that includes Factory-AI/droid-action#144. The tier aliases need a Droid CLI release that includes Factory-AI/factory-mono#22502.

Testing

• npx mint broken-links from docs/: no broken links (this also parses the changed MDX).

[factory-nizar]

Closing: the docs moved to factory-public-web. These changes are now in https://github.com/Factory-AI/factory-public-web/pull/698.