docs(console): sync with current Console - #58279

Docs-only change. I read it against the rest of the Console docs. The edits are consistent with each other and leave no stale references to the removed models in services/www. The public API is unchanged.

The Console behaviour described here (policy budgets and the legacy API's 409, owner-only SSO/SCIM, account linking, leaving a workspace, 403 for free-tier models outside OpenCode, Go privacy defaults) lives in Console code that isn't in this repository, so I couldn't check it against source. A maintainer familiar with the Console should confirm those parts.

One gap: the description says Qwen3.7 Max/Plus are Go only now, but go.mdx lists only Qwen3.7 Plus. After this PR, Qwen3.7 Max isn't documented anywhere. If it's retired, that's fine; if it's still on Go, it should be added there.

Heads-up: #58267 also removes LongCat 2.5 Preview Free from go.mdx and models.mdx (plus the Console marketing page). Whichever merges second will need a rebase.

The new commit puts LongCat 2.5 Preview Free and Nemotron 3 Ultra Free back as they are on the base branch. This PR no longer overlaps with #58267, which removes the LongCat rows. Still docs only, and the public API is unchanged.

One small thing: in go.mdx the restored LongCat note lost the blank line before the Beam Free note, so the two will render as one paragraph (see the inline comment).

• services/www/src/docs/content/console/go.mdx:227: The blank line that separated this note from the Beam Free note on the base branch is gone, so Markdown merges the two into one paragraph. Adding the empty line back restores the original rendering.

The blank line between the LongCat and Beam Free notes in go.mdx is back, so the earlier point is fixed. The new commit's budgets changes are consistent across budgets.mdx and api/budgets.mdx: the API keeps managing single-member limits after migration, the rest is managed in Controls, and the new 409 row in the errors table matches. Nothing new to flag. Still docs only, and the public API is unchanged. The policy and Budgets API behaviour lives in Console code outside this repository, so I couldn't check it against source.

The new commit only rewords api/budgets.mdx. The meaning stays the same, and no links point to the old #return-to-the-workspace-default anchor, so the heading rename breaks nothing. Nothing new to flag. Still docs only, and the public API is unchanged. The Budgets API behaviour lives in Console code outside this repository, so I couldn't check it against source.