[codex] Build contracts v0 foundation

[FlowmemoryAI]

Summary

Builds the FlowMemory contracts V0 foundation into a runnable local Foundry package with compact commitment registries, boundary ADRs, and expanded tests.

Advances #6, #7, #8, #21, #22, #23, #24, #25, #26, #28, #29, #39, #52, and #53.

What changed

• Added root-level foundry.toml so forge test runs from the repository root.
• Hardened RootfieldRegistry with deactivation, owner-only ownership transfer, status FlowPulse emissions, and negative-path tests.
• Added V0 skeletons and interfaces for ArtifactRegistry, CursorRegistry, ReceiptVerifier, WorkerRegistry, VerifierRegistry, WorkDebtScheduler, WorkReceiptRegistry, VerifierReportRegistry, and FlowMemoryHookAdapter.
• Added ADRs for FlowPulse, rootfield boundaries, hook adapter, artifact registry, identity registries, work receipts, verifier reports, and observation identity.
• Updated FlowPulse/security docs to preserve the txHash/logIndex boundary and URI advisory semantics.
• Expanded Foundry tests to 33 passing tests across Rootfield and Live V0 package behavior.

Validation

• forge build
• forge test
• forge fmt --check contracts tests
• git diff --cached --check
• where.exe slither was checked locally; Slither was not available in PATH, so [contracts] Add Slither and static-analysis plan for v0 contracts #24 remains the setup/static-analysis follow-up.

Notes and risks

• Not production audited and not mainnet-ready.
• No tokenomics, dynamic fees, production hooks, external protocol calls, appchain/L1 logic, secrets, or deployment credentials.
• URI strings remain arbitrary advisory event data; callers must keep heavy/sensitive data off-chain.
• Work and verifier allowlists are local owner-controlled V0 policy, not decentralized authorization or Sybil resistance.
• Contract-test CI is not included in this PR because the latest working scope excluded .github/workflows/.

[FlowmemoryAI]

Launch-core direction: please align this contracts PR with issue #63 and docs/V0_LAUNCH_ACCEPTANCE.md. Contracts-side completion should provide evidence for Rootfield namespaces, root commitments, parent/child transition support, and FlowPulse linkage without production hook/deployment claims.

[FlowmemoryAI]

Acceptance audit follow-up: please make the PR summary identify the exact contract tests proving the launch-core rows for Rootfield namespaces, root commitments, parent/child or parentPulseId linkage, and FlowPulse linkage. The required evidence is tracked in docs/reviews/ROOTFLOW_FLOW_MEMORY_V0_ACCEPTANCE_AUDIT.md on PR #59.