Add SourceOS exactness, stale-state, and local-first reasoning-failure contracts

[mdheller]

Parent

SocioProphet/sociosphere#271

Purpose

Capture SourceOS-side contracts for reasoning-failure classes that must be enforced locally: exact strings, stale state, local-first sync, memory contamination, repair evidence, and deterministic verification.

Scope

Add or extend contracts/docs for:

• exactness-sensitive artifacts: IDs, filenames, checksums, signatures, versions, package names, YAML/TOML/JSON, config fields, boot/release refs;
• stale-state and validity-interval metadata;
• observed time vs event time vs valid time;
• local-first contradiction and conflict records;
• repair-plan linkage for reasoning-derived state errors;
• deterministic verifier receipts for string/counting/schema/policy checks;
• source-channel envelopes carrying reasoning-failure refs;
• memory/context hydration boundaries for SourceOS local services.

Acceptance criteria

• SourceOS contracts distinguish durable, rebuildable, and disposable state for reasoning-failure evidence.
• Exactness-sensitive mutations require deterministic verifier evidence and cannot be admitted from model text alone.
• Contract examples cover stale state, string exactness failure, checksum mismatch, conflicting local object facts, and repair-plan preview.
• Downstream sourceos-syncd, agent-machine, sourceos-devtools, AgentPlane, Policy Fabric, and Sociosphere integration points are documented.
• No contract grants live mutation authority by itself.