feat(web): re-land the goals wire domain as mutation-only ref acknowledgements

Six mutation RPCs (create/edit/pause/resume/complete/clear) move into
dsh-host-apiproxy (the PR's host/runtime carrier is gone): goalService()
resolves ctx.get('goals') with a loud absence error, mutateGoal() resolves
the session's agent (agentFor, the command.* implicit-resume precedent) and
acknowledges with the new CAS ref only. GoalError codes ride err.details.

goal.get and the wire GoalView/goalViewSchema are gone: the read side is the
'goal' session projection (whole values on the history tail page and
session/projection frames), so responses never feed client state — the rule
whose absence forced the original PR's write-revision fences.

packages/host/apiproxy/src/api/goals.ts

@@ -1,6 +1,12 @@
 /**
  * goals domain contract. Method signatures are the source of truth:
  * unary methods take the RpcRequest<P> narrow form and the impl echoes rpcId.
+ *
+ * Mutations only: the read side is the 'goal' session projection (history
+ * tail-page projections block + session/projection frames), so there is no
+ * goal.get and no wire goal view — responses acknowledge with the new CAS
+ * ref and never feed client state (the committed goal/change event reaches
+ * every client through the mux stream carrying the same whole value).
  */
 
 import type { Branded } from '@deepseek-ai/dsh-brand'
@@ -16,69 +22,27 @@ export interface GoalRef {
   readonly revision: number
 }
 
-/** Durable continuation phase. */
-export type GoalPhase =
-  | 'active'
-  | 'paused'
-  | 'blocked'
-  | 'complete'
-
-/** Machine-routable and human-readable explanation for a blocked goal. */
-export interface GoalBlockReason {
-  readonly code: string
-  readonly message: string
-}
-
-/** Whether this live process may automatically continue an active goal. */
-export type GoalActivation = 'armed' | 'disarmed'
-
-/** Current goal projection, including values derived from the session log. */
-export interface GoalView {
-  readonly id: GoalId
-  readonly revision: number
-  readonly objective: string
-  readonly phase: GoalPhase
-  readonly blockedReason?: GoalBlockReason
-  readonly maxGoalRounds: number
-  readonly roundsStarted: number
-  readonly createdAt: number
-  readonly updatedAt: number
-  readonly activation: GoalActivation
-}
-
-/** Input whose omitted round cap is resolved by the service configuration. */
-export interface CreateGoalRequest {
-  readonly objective: string
-  readonly maxGoalRounds?: number
-}
-
-/** Fields changed by an edit; at least one must be present. */
-export interface EditGoalRequest {
-  readonly objective?: string
-  readonly maxGoalRounds?: number
-}
-
-/** Goal-domain unary methods (mutations only: the read side is the 'goal' session projection). */
+/** Goal-domain unary methods (every mutation resolves the session's agent and applies one CAS-guarded verb). */
 export interface GoalsApi {
   /** Create and arm a goal. */
   create(request: RpcRequest<{ sessionId: SessionId; objective: string; maxGoalRounds?: number }>):
-  Promise<RpcResponse<{ goal: GoalView }>>
+  Promise<RpcResponse<{ ref: GoalRef }>>
 
   /** Edit objective and/or round cap without changing phase. */
   edit(request: RpcRequest<{ sessionId: SessionId; ref: GoalRef; objective?: string; maxGoalRounds?: number }>):
-  Promise<RpcResponse<{ goal: GoalView }>>
+  Promise<RpcResponse<{ ref: GoalRef }>>
 
   /** Pause an active goal and disarm automatic continuation. */
   pause(request: RpcRequest<{ sessionId: SessionId; ref: GoalRef }>):
-  Promise<RpcResponse<{ goal: GoalView }>>
+  Promise<RpcResponse<{ ref: GoalRef }>>
 
   /** Resume and arm a stopped goal. */
   resume(request: RpcRequest<{ sessionId: SessionId; ref: GoalRef }>):
-  Promise<RpcResponse<{ goal: GoalView }>>
+  Promise<RpcResponse<{ ref: GoalRef }>>
 
   /** Mark a current non-complete goal complete and disarm it. */
   complete(request: RpcRequest<{ sessionId: SessionId; ref: GoalRef }>):
-  Promise<RpcResponse<{ goal: GoalView }>>
+  Promise<RpcResponse<{ ref: GoalRef }>>
 
   /** Clear the current goal while retaining a durable tombstone and history. */
   clear(request: RpcRequest<{ sessionId: SessionId; ref: GoalRef }>):