fix: preserve dependency edges for relative tree-sitter file paths

[daBOB]

The shared tree-sitter dependency builder drops valid imports when discovered file keys are project-relative: it normalizes resolver output to absolute paths and compares those against the original relative key set. Normalize membership lookups while preserving the caller-visible graph keys, including the existing scan-relative resolver fallback.

This addresses the path-normalization portion of #715. CommonJS query expansion is outside this change.

Validation:

• Six real-parser regressions cover relative, dotted, absolute and mixed JavaScript keys, the generic file-discovery integration, Kotlin absolute resolver output, and exclusion of an existing file outside the scanned set. Before the fix: five failed, one passed. After: all six pass.
• Shared-language and JavaScript suites: 512 passed, 2 skipped. Scoped Ruff and formatting checks pass.
• Full desloppify/tests/: 5814 passed, 5 skipped, 2 failed. Both failures are the existing TestCmdReviewPrepare::test_do_run_batches_dry_run_generates_packet_and_prompts assertion that prompts contain Previously flagged issues (unit and integration wrappers). Both reproduce on pristine upstream HEAD 3a7735d without this patch.
• Read-only validation against 52 authored browser modules restores 126 static import edges and 51 imported modules, previously zero. An Android multi-module tree still has no resolved edges due to the separate Kotlin resolver source-root limitation; this change does not claim to repair that resolver.

No suppressions, score changes, or language-query changes.