Return each embedded ACP adapter to a qualifying upstream release

[taras]

Purpose

Issue #622 embeds one npm tarball per provider under packages/acp/vendor/adapters and runs those instead of the adapter npx would resolve, because no published Codex or Claude release names the turn a Prompt completed.

Provider	Package	Version	Contract	Upstream PR
codex	@agentclientprotocol/codex-acp	1.6.2	_meta.codex.turnId	agentclientprotocol/codex-acp#438
claude	@agentclientprotocol/claude-agent-acp	0.70.0	_meta.claudeCode.assistantMessageUuid	agentclientprotocol/claude-agent-acp#1047

Remove each snapshot when an exact upstream release carries its contract. The two are independent: one provider may return to a published release while the other's snapshot stays, and this issue closes only when both have.

This is not an adapter upgrade. Returning to a release and moving to a newer adapter are separate changes and are not done together.

Exit gate, per provider

A candidate release replaces that provider's snapshot only when all of these pass on one exact revision:

• a normally completed prompt's response carries the contract above, and the value is byte-for-byte the identity the provider surface emitted;
• interleaved turns each carry their own identity, so nothing session-global is being read;
• cancelled, failed, refused, malformed, ambiguous and metadata-free completions each carry none, and nothing reconstructs one;
• the released version is selected exactly, never through a moving range;
• Tier AD, Tier AM and the Retain provider checkpoint tokens for workflow Agent Prompts #622 T1 evidence pass against the released adapter with no alternative token source added; and
• the Deno cached/no-node-modules build and release compile, the npm package, the JSR dry run and the repository clean/composability verifier pass.

Removal, per provider

• drop that provider's tarball and LICENSE from packages/acp/vendor/adapters/<provider>/;
• remove its entry from MANIFEST.json and regenerate generated/snapshots.ts;
• remove its REVIEWED entry and any provider-specific case from scripts/tests/adapter-vendor.test.ts;
• restore that provider to the published command in the registry the workflow Agent profile installs, keeping the registry closed to the providers this host serves; and
• update packages/acp/vendor/adapters/PROVENANCE.md.

When the last snapshot goes, remove packages/acp/src/adapter-snapshots.ts, scripts/build-adapter-snapshots.ts, Tier AD and Tier AM, and the adapters seam on the workflow Agent profile.

Not this issue

• Remove the vendored ACPX checkpoint-metadata patch after a released runtime carries response _meta #629 owns the vendored ACPX checkpointMeta patch, and Remove the vendored ACPX transient-environment patch after a released scoped seam passes continuity #566 owns the ACPX agentProcessEnv patch. Those patch a runtime this repository imports; this issue is about whole packages it executes.
• The retention contract. What a checkpoint is, and what a run does with one, is specs/workflow-workspace-spec.md §8.6 and does not change when a snapshot is removed.

Context

• packages/acp/vendor/adapters/PROVENANCE.md
• packages/acp/src/adapter-snapshots.ts
• Tier AD: scripts/tests/adapter-vendor.test.ts
• Tier AM: packages/acp/tests/adapter-materialization.test.ts