fix(web,mobile): T3 no longer offers or starts context compaction

apps/mobile/src/features/threads/NewTaskDraftScreen.tsx

@@ -523,7 +523,6 @@ export function NewTaskDraftScreen(props: {
     projectCwd: composerWorkspaceCwd,
     selectedProviderStatus: flow.selectedProviderStatus,
     hasThread: false,
-    hasCompactableConversation: false,
     offersUsageLimits: offersUsageLimits,
     enabled: isComposerFocused && !isComposerInteractionLocked,
     onChangeDraftMessage: flow.setPrompt,

apps/mobile/src/features/threads/ThreadComposer.tsx

@@ -153,7 +153,6 @@ export interface ThreadComposerProps {
   readonly threadSyncPhase?: "loading" | "syncing" | null;
   readonly selectedThread: EnvironmentThreadShell;
   readonly reportedModelSelection?: ModelSelection | null;
-  readonly hasCompactableConversation: boolean;
   readonly serverConfig: T3ServerConfig | null;
   readonly queueCount: number;
   readonly activeThreadBusy: boolean;
@@ -495,7 +494,6 @@ export const ThreadComposer = memo(function ThreadComposer(props: ThreadComposer
     pullRequestRepository: project?.repositoryIdentity?.displayName ?? null,
     selectedProviderStatus,
     hasThread: true,
-    hasCompactableConversation: props.hasCompactableConversation,
     onChangeDraftMessage: props.onChangeDraftMessage,
     onUpdateInteractionMode:
       selectedProviderStatus?.showInteractionModeToggle === false

apps/mobile/src/features/threads/ThreadDetailScreen.tsx

@@ -498,16 +498,6 @@ export const ThreadDetailScreen = memo(function ThreadDetailScreen(props: Thread
       (entry) => "acknowledged" in entry && entry.acknowledged === true,
     );
   const selectedThreadFeed = props.selectedThreadFeed;
-  const hasCompactableConversation =
-    selectedThreadFeed.some(
-      (entry) =>
-        entry.type === "message" &&
-        entry.message.role === "user" &&
-        ((entry.message.attachments?.length ?? 0) > 0 ||
-          entry.message.text.trim().toLowerCase() !== "/compact"),
-    ) ||
-    (props.historyControls?.hasMoreHistory === true &&
-      props.selectedThread.latestUserMessageAt !== null);
   const composerChrome = composerExpanded ? COMPOSER_EXPANDED_CHROME : COMPOSER_COLLAPSED_CHROME;
   const composerOverlapHeight = composerChrome + composerBottomInset;
   // While a user-input request is pending, the questionnaire owns the
@@ -1309,7 +1299,6 @@ export const ThreadDetailScreen = memo(function ThreadDetailScreen(props: Thread
                       connectionState={props.connectionStateLabel}
                       environmentLabel={props.environmentLabel}
                       selectedThread={props.selectedThread}
-                      hasCompactableConversation={hasCompactableConversation && !props.isCompacting}
                       serverConfig={props.serverConfig}
                       queueCount={props.selectedThreadQueueCount}
                       activeThreadBusy={props.activeThreadBusy}

apps/mobile/src/features/threads/use-composer-command-menu.ts

@@ -58,7 +58,6 @@ export function buildComposerSlashCommandItems(input: {
   readonly query: string;
   readonly atMessageStart: boolean;
   readonly hasThread: boolean;
-  readonly hasCompactableConversation?: boolean;
   /** Whether T3 itself offers /usage-limits for the selected provider. */
   readonly offersUsageLimits?: boolean;
   readonly allowInteractionMode: boolean;
@@ -102,7 +101,6 @@ export function buildComposerSlashCommandItems(input: {
   if (!input.atMessageStart) return items;
   for (const command of input.selectedProviderStatus?.slashCommands ?? []) {
     if (!command.name.toLowerCase().includes(query)) continue;
-    if (command.name === "compact" && !input.hasCompactableConversation) continue;
     // T3's own limits command is answered by the thread composer; New Task has
     // nowhere to show it. A provider's same-named command is left alone.
     if (command.name === USAGE_LIMITS_COMMAND.name && input.offersUsageLimits && !input.hasThread) {
@@ -176,7 +174,6 @@ export function useComposerCommandMenu({
   pullRequestRepository = null,
   selectedProviderStatus,
   hasThread,
-  hasCompactableConversation,
   offersUsageLimits = false,
   enabled = true,
   onChangeDraftMessage,
@@ -195,7 +192,6 @@ export function useComposerCommandMenu({
   readonly pullRequestRepository?: string | null;
   readonly selectedProviderStatus: ServerProvider | null;
   readonly hasThread: boolean;
-  readonly hasCompactableConversation: boolean;
   /** Whether T3 itself offers /usage-limits for the selected provider. */
   readonly offersUsageLimits?: boolean;
   readonly enabled?: boolean;
@@ -347,7 +343,6 @@ export function useComposerCommandMenu({
         query: q,
         atMessageStart: trigger.rangeStart === 0,
         hasThread,
-        hasCompactableConversation,
         offersUsageLimits,
         allowInteractionMode: onUpdateInteractionMode !== undefined,
         selectedProviderStatus: selectedProviderStatus
@@ -488,7 +483,6 @@ export function useComposerCommandMenu({
     environmentId,
     threadShells,
     hasThread,
-    hasCompactableConversation,
     onUpdateInteractionMode,
     pathSearch.entries,
     pullRequestSearch.entries,