fix(js): follow tsconfig references so solution-file path aliases resolve (#3745)

[abhay-codes07]

Fixes #3745.

What

_read_tsconfig_aliases follows extends chains but never references. In the standard Vite / tsc -b layout the root tsconfig.json is a solution file — "files": [] with references: [{ "path": "./tsconfig.app.json" }, …] — and every compilerOptions.paths block lives in a referenced project config. The loader walks up, finds the solution file, sees no paths and no extends, and stops.

The effect: every path-alias import in the project silently produces no imports_from edge. The specifier lands on a dangling ref_* node, and graphify affected <module> returns a partial consumer set with no warning. On the reporter's Vite + React app, 0 of 2,024 alias imports resolved (relative imports were 100%).

Root cause

references is a first-class TypeScript project-linking mechanism, distinct from extends. _read_tsconfig_aliases handled extends (string or array) but the references list was never read, so a solution-style root yielded {}.

Fix

After the extends loop, follow references the same way: merge each referenced config's aliases like an additional parent (the referencing config's own paths still override), guarded by the existing seen set that protects extends against cycles. A reference path may name a directory (resolved to its tsconfig.json, as tsc -b does) or a config file directly.

Verification

• Reproduced the minimal solution-file layout from the issue: before, src/a.ts -imports_from-> ref_app_b (dangling); after, src/a.ts -imports_from-> src/b.ts (resolved).
• Two regression tests (solution-file reference, directory-valued reference) — both fail on the unpatched loader and pass with the fix.
• No regressions: the JS/TS import-resolution, jsconfig-baseUrl, extension-resolution, and Astro suites stay green (135 tests).

Notes

The prior attempt at this (#3631) was closed 2026-09-17 to be resubmitted and hasn't reappeared; this is an independent, minimal fix scoped to alias discovery. replace-style edge cases (vendor/, go.work analogues) don't apply to tsconfig; the seen guard makes the reference walk cycle-safe.

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