Fix Sentry package bugs: name mismatch and FAT static detection

[guitaripod]

Fixes #130

Problem

1. Framework name mismatch: Sentry-Dynamic.xcframework contains Sentry.framework, but xtool looked for Sentry-Dynamic.framework

2. FAT static detection: FAT binaries (0xCAFEBABE) containing static archive slices were misidentified as dynamic

Solution

1. Added findFrameworkName() to scan binDir when expected framework name doesn't exist, matching by binary header or prefix

2. Enhanced isStaticBinary() to parse FAT headers and check slice magic (!<arch>\n) instead of just checking outer magic

Verification

# Framework name resolution
Sentry-Dynamic.xcframework/ios-arm64/ contains Sentry.framework (not Sentry-Dynamic.framework)
Build log shows: "Copying Sentry.framework" ✓

# Binary detection
Static Sentry:  FAT (cafebabe) → slice @ 48    → !<arch>\n  → static ✓
Dynamic Sentry: FAT (cafebabe) → slice @ 32768 → cffaedfe   → dynamic ✓

Test Plan

Linux

• Unit test isStaticBinary() - correctly identifies static vs dynamic
• Unit test findFrameworkName() - resolves Sentry-Dynamic → Sentry
• xtool builds successfully

macOS

• Verify xcframework contains mismatched name (Sentry.framework inside Sentry-Dynamic.xcframework)
• Verify static Sentry is FAT binary with archive slices
• Verify dynamic Sentry is FAT binary with Mach-O slices
• Framework name resolution works (build log: "Copying Sentry.framework")
• Full e2e build blocked by unrelated bug (empty stub.c)