synth v0.49.0

What's Changed

• feat(#77,#80): platform space-consistency invariant + P3 async error-context.drop lowering by @avrabe in #810
• feat(#782): sound ARM32 i64 trunc_sat via branch-free FP decompose — falcon skip 4→0 by @avrabe in #812
• feat(#778): WCET phase 4 — bounded self-recursion via a verified depth-hint by @avrabe in #813
• fix(#761): separate R9 globals base from linmem page — kill the self-contained --cortex-m alias by @avrabe in #811
• proof(#242): VCR-WASM-001 i64 transcription batch — 22 ops, 536→585 Qed by @avrabe in #814
• test(vcr-sel-005): universe-complete cross-backend op-parity gate — surface 16 silent ARM/RV32 op-gaps (#242, #223, #232) by @avrabe in #816
• feat(#242): VCR-RA-003 phase 2 — across-CALL + across-JOIN allocation validation (whole-function) by @avrabe in #817
• chore(release): v0.49.0 — phase-2 frontier + falcon to zero by @avrabe in #818

Full Changelog: v0.48.0...v0.49.0