fix(rust): normalize raw crate identifiers

[rowkav09]

Closes #583.

Strip the r# raw identifier syntax before matching Rust crate roots against manifest dependencies. Same normalization applies to excluded builtin roots. Previously use r#try::Thing and r#try::run() returned no usage for dependency try.

Fail-first regression reproduces missing lines1/2. After patch all79 Rust tests+lint green.

[rowkav09]

APPROVE at 91a2b1a

collectReferences now strips a leading r# from the crate path root before the exclusion check and before recording the reference, so r#try::run() and use r#try::Thing both match a dependency named try. The test checks both lines (1 and 2). Rust adapter suite on the head merged with main: 79/79.

Minor, not blocking: the imported symbol name is not stripped, so use foo::r#type would record the symbol as "r#type". It only affects the symbol label, not whether the usage is found.

CI: not checked by me; the lane merges on APPROVE plus green CI.

Reviewed as rowkav09, the same account as the author, so this is not an independent GitHub approval.

[rowkav09]

Re-ack at df323c2: APPROVE.

Rebase only. The source change is the same as the head I approved earlier (91a2b1a): the r# strip in collectReferences, 2 files changed. The test conflict is resolved and the Rust adapter suite on the head merged with main passes, 80/80. Reviewed as rowkav09, the same account as the author, so this is not an independent GitHub approval.