fix(apex): emit extends edges for interface multiple inheritance

[Synvoya]

What it fixes

An Apex interface X extends A, B emitted only a contains edge — the parent interface list was dropped from the graph.

iface_re captures the extends parent list in group 2, but the interface handler read only group 1 (the interface name); group 2 was never used. (The class branch already splits its parent list and emits an edge per parent.)

Fix

After the interface node / contains edge, iterate the captured parent list and emit one extends edge per parent, mirroring the class branch's node resolution (extends matches the keyword Apex interfaces use for inheritance; the class branch already emits extends). Apex interfaces support multiple inheritance.

public interface PaymentProcessor extends Processor, Auditable { void process(); }

now emits:

extends: PaymentProcessor -> Processor
extends: PaymentProcessor -> Auditable

Test

• tests/test_languages.py: test_apex_interface_extends asserts both parents appear as inheritance edges.
• pytest tests/test_languages.py -k apex → 13 passed (negative control without the fix fails with an empty inheritance set).

[safishamsi]

Merged into v8 as 53c769d, with your authorship preserved (ships in 0.9.6). Thanks @Synvoya.

Clean fix — the interface handler was reading only group 1 while group 2 already captured the parent list, and your addition mirrors the class branch's parent resolution exactly (same stem/bare _make_id fallback and INFERRED confidence). The negative-control note on the test was appreciated.