multiformats: rewrite CID (cid_v0 + cid_v1) module

[uink45]

Summary

• rewrote cid_v0 and cid_v1 implementations with bounded parsing/encoding flow and deterministic failure-state resets
• redesigned cid_v1 ownership to internal bounded storage (CIDV1_MAX_MULTIHASH_SIZE) and removed heap allocation from CID rewrite scope
• tightened CIDv1 multihash validation (version/codec varints + exact payload framing) for both bytes and string decode paths
• expanded base-prefix handling in CIDv1 decode to include upper-case multibase prefixes where applicable
• replaced CID test suites with broader vector-driven positive/negative/boundary coverage and known-vector regressions

Files Changed

• include/multiformats/cid/cid_v0.h
• include/multiformats/cid/cid_v1.h
• src/multiformats/cid/cid_v0.c
• src/multiformats/cid/cid_v1.c
• tests/multiformats/cid/test_cid_v0.c
• tests/multiformats/cid/test_cid_v1.c

Rewrite Process Artifacts

• standards mapping + remediation record (Step 3/7/8):
  • /Users/multi/Documents/GitHub/libp2p/standards/rewrite-pilot-4-cid-v0-v1.md

Validation

• cmake --build --preset macos-full --target cid_v0 cid_v1 test_cid_v0 test_cid_v1
• ctest --preset macos-full -R '^(Testcid_v0|Testcid_v1)$' --output-on-failure
• cmake --build --preset macos-full --target multibase cid_v0 cid_v1 test_multibase test_cid_v0 test_cid_v1 multiaddr test_multiaddr peer_id test_peer_id
• ctest --preset macos-full -R '^(Testmultibase|Testcid_v0|Testcid_v1|Testmultiaddr|Testpeer_id)$' --output-on-failure
• cmake --preset linux-asan-ubsan
• cmake --build --preset linux-asan-ubsan --target test_cid_v0 test_cid_v1
• ctest --preset linux-asan-ubsan -R '^(Testcid_v0|Testcid_v1)$' --output-on-failure
• clang-format --style=file --dry-run --Werror include/multiformats/cid/cid_v0.h include/multiformats/cid/cid_v1.h src/multiformats/cid/cid_v0.c src/multiformats/cid/cid_v1.c tests/multiformats/cid/test_cid_v0.c tests/multiformats/cid/test_cid_v1.c
• cppcheck --error-exitcode=1 --std=c99 --enable=warning,portability --quiet --suppress=missingIncludeSystem src/multiformats include/multiformats tests/multiformats src/peer_id include/peer_id tests/peer_id
• cppcheck --std=c99 --enable=all --check-level=exhaustive --quiet --suppress=missingIncludeSystem --suppress='*:tests/*' --addon=<misra.py> -I include src/multiformats/cid include/multiformats/cid tests/multiformats/cid
• scripts/dev/run-fast-lane-local.sh --platform macos