Add workspace sync operation contracts and DecisionCard conflict semantics

[Copilot]

This PR integrates sourceos-syncd into the local-first workspace sync contract surface by introducing explicit operation/task state for sync workflows and tightening conflict handling semantics. It also aligns fixtures/docs so downstream integrations can consume policy-gated, evidence-linked sync records consistently.

• Workspace sync state contracts

  • Added sourceos.workspace-operation/v1alpha1 via WorkspaceOperationRecord
  • Added sourceos.operation-task/v1alpha1 via OperationTaskRecord
  • Captures required local-first sync responsibilities:
    • local_operation_id ↔ remote_operation_id
    • provisional artifact IDs + final reconciliation
    • checkpoint refs + causal parent linkage
    • stale task / lease expiry / replay safety flags
    • policy, artifact admission, and ledger evidence references

• Required operation type enforcement

  • Added controlled values for required operation types:
    • sync.operation.enqueue
    • sync.operation.replay
    • sync.operation.reconcile
    • sync.conflict.detect
    • sync.conflict.resolve
    • sync.repair.apply
    • sync.tombstone.apply
    • sync.checkpoint.write
  • Applied to both workspace operations and operation tasks.

• Conflict DecisionCard semantics

  • Extended ConflictRecord to require a decision_card object.
  • Added validation for option-set semantics (merge / fork / skip) and selected/recommended option consistency.

• Fixtures and contract coverage

  • Added new fixtures:
    • examples/contracts/workspace-operation.alpha.json
    • examples/contracts/operation-task.alpha.json
  • Updated conflict fixture to include decision_card.
  • Extended contract tests to:
    • validate and round-trip new schemas
    • reject invalid operation types
    • reject invalid DecisionCard options

• Contract documentation updates

  • Updated docs/contracts.md with:
    • new schema families
    • new fixture inventory
    • workspace operation type set
    • DecisionCard option semantics

{
  "schema": "sourceos.workspace-operation/v1alpha1",
  "operation_type": "sync.operation.reconcile",
  "local_operation_id": "local-op:0001",
  "remote_operation_id": "remote-op:9931",
  "provisional_artifact_ids": { "artifact:temp-1": "object:alpha" },
  "artifact_reconciliation": { "artifact:temp-1": "artifact:final-44" },
  "checkpoint_ref": "checkpoint:workspace-default-0001",
  "causal_parent_ids": ["local-op:0000"],
  "policy_decision_ref": "policy-decision:review-alpha",
  "ledger_evidence_refs": ["evidence:operation-0001"],
  "replay_safe": true
}