feat(r8-tests): Add R8 inline tests (#69)

Part of #40 

There are failing tests in this PR that need fixes in the mapper/cache
itself, so I will open a follow-up PR that targets this branch.

## R8 Retrace Test Coverage
- [x] Inlining (13 tests) - inline frames, line numbers, source files,
rewriteFrame rules
- [ ] Ambiguous Methods (7 tests) - multiple methods → same obfuscated
name, <OR> alternatives
- [x] Outlines (4 tests) - outline callsites, nested outlines,
inline-in-outline
- [ ] Synthetic/Lambda (3 tests) - lambda methods, synthetic bridges
- [ ] Source File Edge Cases (7 tests) - colons, unicode, multiple dots,
synthesized names
- [ ] Line Number Handling (10 tests) - spans, preambles, invalid
ranges, missing lines
- [ ] Exception Handling (6 tests) - obfuscated exceptions, suppressed,
circular refs
- [ ] Method Overloading (4 tests) - overloads with/without ranges
- [ ] Mapping Versions (2 tests) - version warnings, multiple versions
- [ ] Special Formats (4 tests) - Java 9+ modules, logcat format,
auto-detect
- [ ] Identity/Passthrough (2 tests) - identity mappings
- [ ] Real-World Bot Tests (4 tests) - production stack traces
- [ ] Edge Cases (6 tests) - invalid input, dashes in names, whitespace,
field overlap

Author: romtsn