feat: initial meshservice implementation

Generic decentralized service layer for mesh networks.
Includes FAPP (psychotherapy) and Housing as reference services.

- ServiceMessage with Ed25519 signatures
- Wire protocol (64-byte header + CBOR)
- ServiceRouter with pluggable handlers
- Verification framework (3 trust levels)
- 32 tests, 3 examples

target/debug/.fingerprint/rand-71a9dcf5c78a8436/invoked.timestamp

@@ -0,0 +1 @@
+This file has an mtime of when this was started.

target/debug/.fingerprint/rand-71a9dcf5c78a8436/lib-rand

@@ -0,0 +1 @@
+ebb3381e9388370c

target/debug/.fingerprint/rand-71a9dcf5c78a8436/lib-rand.json

@@ -0,0 +1 @@
+{"rustc":1100337564441796057,"features":"[\"alloc\", \"default\", \"getrandom\", \"libc\", \"rand_chacha\", \"std\", \"std_rng\"]","declared_features":"[\"alloc\", \"default\", \"getrandom\", \"libc\", \"log\", \"min_const_gen\", \"nightly\", \"packed_simd\", \"rand_chacha\", \"serde\", \"serde1\", \"simd_support\", \"small_rng\", \"std\", \"std_rng\"]","target":8827111241893198906,"profile":15657897354478470176,"path":3742964201048712603,"deps":[[1573238666360410412,"rand_chacha",false,17151806753264722714],[17159683253194042242,"libc",false,9010325384394673773],[18130209639506977569,"rand_core",false,10357312256965701952]],"local":[{"CheckDepInfo":{"dep_info":"debug/.fingerprint/rand-71a9dcf5c78a8436/dep-lib-rand","checksum":false}}],"rustflags":[],"config":2069994364910194474,"compile_kind":0}