fix(models): preserve explicitly configured maxTokens when window-capping

[Leechael]

Stacked on #59 — merge after it

#59 is from a fork, so its branch can't be a PR base here; this PR targets main and its diff will shrink to the single fix commit once #59 merges.

What

#59 window-caps every built model's maxTokens at its context window via withWindowCappedMaxTokens, which silently discards an explicitly configured model.maxTokens — home, project, and runtime settings all get reset to the window. This PR preserves the explicit cap and applies the window value only for the default/unset case.

How

• "Unset" is detected by value (maxTokens === built-in default 32000), not by config source: ensureKimiCodeConfig materializes the full default config (including maxTokens) into the home config file, so source tracking reports home for users who never set the field — source-based detection would defeat the window-cap for exactly the users it targets.
• Window-tracked caps follow discovery: buildKimiModelFromConfig caps before discovery runs, so applyKimiOAuthExtrasToModel captures the window-tracked state before extras grow the window, and only re-caps maxTokens to the new window when it was tracking. Explicit caps survive discovery unchanged.

Known edges (documented in code)

• An explicit maxTokens: 32000 is indistinguishable from a materialized default and gets the window cap — acceptable, since that is the intended new default behavior.
• An explicit value equal to the context window is treated as window-tracked (harmless: value equals the window anyway).

Tests

Two new cases: explicit cap preserved at build time, and preserved when discovery grows the window. tsc --noEmit, oxlint, and the full suite pass (235/235).

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Summary by cubic

Preserves explicitly configured max tokens when window-capping models, so user-set limits are not overwritten. The window cap now applies only when the value is unset (default) or already tracking the window.

• Bug Fixes
  • Detect “unset” by value (32000) instead of config source to handle materialized defaults.
  • Track window-capped state across discovery; re-cap only if it was tracking, keep explicit caps unchanged.
  • Added tests for build-time and for discovery when the window grows.

^{Written for commit e622aa9. Summary will update on new commits.}

[github-actions]

CI summary

• Test coverage: Lines 91.73, branches 80.85, functions 90.59
• Package size: Packed 56 KB, unpacked 204 KB, files 18

Check	Result
Tests	passed
Type check	success
Lint	success
Format	success

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}