feat: expand slash-command goals from command templates

Resolves armed slash-command objectives from authoritative templates before dispatch
Applies OpenCode argument expansion for goal metadata in UI and scheduled tasks
Falls back to the raw invocation when command details are unavailable

packages/ui/src/sync/session-ui-store.ts

@@ -73,6 +73,34 @@ import { rememberRuntimeLiveStatus } from "./runtime-live-memory"
 
 export type { AttachedFile }
 
+type GoalCommand = { name: string; template?: string }
+
+export function expandSlashCommandGoalObjective(content: string, commands: GoalCommand[]): string {
+  if (!content.startsWith("/")) return content
+  const [head, ...tail] = content.split(" ")
+  const command = commands.find((candidate) => candidate.name === head.slice(1))
+  if (!command?.template?.trim()) return content
+  const argumentsText = tail.join(" ")
+  if (command.template.includes("$ARGUMENTS")) {
+    return command.template.replaceAll("$ARGUMENTS", argumentsText)
+  }
+
+  const positions = [...command.template.matchAll(/\$(\d+)/g)].map((match) => Number(match[1]))
+  if (positions.length > 0) {
+    const parsedArguments = [...argumentsText.matchAll(/"([^"]*)"|'([^']*)'|(\S+)/g)]
+      .map((match) => match[1] ?? match[2] ?? match[3] ?? "")
+    const lastPosition = Math.max(...positions)
+    return command.template.replace(/\$(\d+)/g, (_match, value: string) => {
+      const position = Number(value)
+      return position === lastPosition
+        ? parsedArguments.slice(position - 1).join(" ")
+        : (parsedArguments[position - 1] ?? "")
+    })
+  }
+
+  return argumentsText ? `${command.template}\n\n${argumentsText}` : command.template
+}
+
 // ---------------------------------------------------------------------------
 // Send routing — shell mode, slash commands, or normal prompt
 // ---------------------------------------------------------------------------
@@ -1052,15 +1080,33 @@ export const useSessionUIStore = create<SessionUIState>()((set, get) => ({
       )
       additionalParts = [...(additionalParts ?? []), { text: goalIntro, synthetic: true }]
     }
-    const applyArmedGoal = (goalSessionId: string, goalDirectory: string | null | undefined) => {
+    const applyArmedGoal = async (goalSessionId: string, goalDirectory: string | null | undefined) => {
       if (!goalArmed) return
       const uiState = useUIStore.getState()
       const tokenBudget = uiState.sessionGoalDefaultBudgetEnabled ? uiState.sessionGoalDefaultBudget : null
-      const objective = goalArm.objectiveOverride?.trim() || content
-      void setSessionGoal(goalSessionId, goalDirectory ?? undefined, { objective, tokenBudget }, null)
-        .catch((error) => {
-          console.warn("[session-ui-store] failed to set goal from armed send", error)
-        })
+      let objective = goalArm.objectiveOverride?.trim() || content
+      if (!goalArm.objectiveOverride && content.startsWith("/")) {
+        const directoryCommands = getDirectoryState(goalDirectory ?? undefined)?.command ?? []
+        const storedCommands = useCommandsStore.getState().commands
+        const knownCommands = [...directoryCommands, ...storedCommands]
+        objective = expandSlashCommandGoalObjective(content, knownCommands)
+        if (objective === content) {
+          try {
+            objective = expandSlashCommandGoalObjective(
+              content,
+              await opencodeClient.listCommandsWithDetails(goalDirectory),
+            )
+          } catch {
+            // Command dispatch remains authoritative; raw invocation is a safe objective fallback.
+          }
+        }
+      }
+      try {
+        await setSessionGoal(goalSessionId, goalDirectory ?? undefined, { objective, tokenBudget }, null)
+      } catch (error) {
+        useSessionGoalArmStore.getState().setArmed(true, goalArm.objectiveOverride)
+        throw error
+      }
     }
 
     // ---- New session from draft ----
@@ -1088,6 +1134,7 @@ export const useSessionUIStore = create<SessionUIState>()((set, get) => ({
         filename: a.filename,
       }))
 
+      await applyArmedGoal(createdDraftSession.sessionId, createdDraftSession.directory)
       await routeMessage({
         sessionId: createdDraftSession.sessionId,
         directory: createdDraftSession.directory,
@@ -1111,7 +1158,6 @@ export const useSessionUIStore = create<SessionUIState>()((set, get) => ({
           })),
         })),
       })
-      applyArmedGoal(createdDraftSession.sessionId, createdDraftSession.directory)
       return
     }
 
@@ -1168,6 +1214,9 @@ export const useSessionUIStore = create<SessionUIState>()((set, get) => ({
       filename: a.filename,
     }))
 
+    if (targetSessionId) {
+      await applyArmedGoal(targetSessionId, currentSessionDirectory)
+    }
     await routeMessage({
       sessionId: targetSessionId || "",
       directory: currentSessionDirectory,
@@ -1191,9 +1240,6 @@ export const useSessionUIStore = create<SessionUIState>()((set, get) => ({
         })),
       })),
     })
-    if (targetSessionId) {
-      applyArmedGoal(targetSessionId, currentSessionDirectory)
-    }
   },
 
   // ---------------------------------------------------------------------------