diff --git a/apps/server/src/orchestration-v2/ProjectionStore.test.ts b/apps/server/src/orchestration-v2/ProjectionStore.test.ts
index 1ca7eb67036fa..5c944096ed89d 100644
--- a/apps/server/src/orchestration-v2/ProjectionStore.test.ts
+++ b/apps/server/src/orchestration-v2/ProjectionStore.test.ts
@@ -1974,6 +1974,14 @@ it.effect("SQL shells read a subagent family and a worktree's threads", () =>
     yield* createThread({ name: "archived-child", parent: "root", root: "root", archived: true });
     yield* createThread({ name: "other", worktreePath: "/repo" });
     yield* createThread({ name: "other-child", parent: "other", root: "other", worktreePath });
+    yield* createThread({
+      name: "aliased-child",
+      parent: "other",
+      root: "other",
+      worktreePath: `${worktreePath}/`,
+    });
+    yield* createThread({ name: "cased", worktreePath: worktreePath.toUpperCase() });
+    yield* createThread({ name: "windows", worktreePath: "C:\\RÉPO\\wt" });
 
     const family = (threadId: ThreadId) =>
       store
@@ -1985,11 +1993,20 @@ it.effect("SQL shells read a subagent family and a worktree's threads", () =>
     assert.sameMembers([...(yield* family(id("grandchild")))], tree);
     assert.deepEqual([...(yield* family(id("missing")))], []);
 
-    // Includes another root's idle child on the same path, which a shell may leave out.
+    // Includes another root's idle child on the same path, which a shell may leave out, under any
+    // spelling of that path. POSIX paths keep their case.
     const onWorktree = yield* store.getShellSnapshot({ location: "active", worktreePath });
     assert.sameMembers(
       onWorktree.threads.map((thread) => thread.id),
-      [id("root"), id("child"), id("other-child")],
+      [id("root"), id("child"), id("other-child"), id("aliased-child")],
+    );
+    const onWindowsWorktree = yield* store.getShellSnapshot({
+      location: "active",
+      worktreePath: "c:/répo/wt/",
+    });
+    assert.deepEqual(
+      onWindowsWorktree.threads.map((thread) => thread.id),
+      [id("windows")],
     );
     // A fork keeps its deleted source's root, so the deleted root still names the live tree.
     yield* store.apply({
diff --git a/apps/server/src/orchestration-v2/ProjectionStore.ts b/apps/server/src/orchestration-v2/ProjectionStore.ts
index 3d33f76b7a494..7b25e74a4f23f 100644
--- a/apps/server/src/orchestration-v2/ProjectionStore.ts
+++ b/apps/server/src/orchestration-v2/ProjectionStore.ts
@@ -95,6 +95,7 @@ import * as SqlClient from "effect/sql/SqlClient";
 import type * as Statement from "effect/sql/Statement";
 
 import { MCP_APP_OUTPUT_KEY } from "@t3tools/shared/mcpApp";
+import { normalizeProjectPathForComparison } from "@t3tools/shared/path";
 import { threadHtmlRenderAttachmentIds } from "../attachmentStore.ts";
 import {
   isThreadHistoryUserTurn,
@@ -1024,6 +1025,7 @@ type ShellThreadRow = {
   readonly thread_id: string;
   readonly payload_json: string;
   readonly forked_from_run_source_thread_id: string | null;
+  readonly worktree_path: string | null;
   readonly latest_run_id: string | null;
   readonly latest_run_status: string | null;
   readonly latest_run_requested_at: string | null;
@@ -6215,6 +6217,7 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
                   THEN json_extract(t.payload_json, '$.forkedFrom.threadId')
                 ELSE NULL
               END AS forked_from_run_source_thread_id,
+              json_extract(t.payload_json, '$.worktreePath') AS worktree_path,
               presented.run_id AS latest_run_id,
               presented.status AS latest_run_status,
               presented.requested_at AS latest_run_requested_at,
@@ -6414,7 +6417,11 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
             }${
               worktreePath === undefined
                 ? sql``
-                : sql` AND json_extract(t.payload_json, '$.worktreePath') = ${worktreePath}`
+                : // Loose match of any spelling of the path; readShellSnapshotRows keeps exact ones.
+                  // SQLite's lower() folds only ASCII, so other paths always reach that check.
+                  sql` AND (json_extract(t.payload_json, '$.worktreePath') GLOB '*[^ -~]*'
+                    OR lower(rtrim(replace(trim(json_extract(t.payload_json, '$.worktreePath')), '\\', '/'), '/'))
+                      = lower(rtrim(replace(trim(${worktreePath}), '\\', '/'), '/')))`
             }${threadIds === undefined ? sql`` : sql` AND t.thread_id IN (SELECT value FROM json_each(${encodeIdList(threadIds)}))`}
             ORDER BY t.updated_at ASC, t.thread_id ASC
           `;
@@ -6971,7 +6978,16 @@ export const layer: Layer.Layer<ProjectionStoreV2, never, SqlClient.SqlClient> =
     const readShellSnapshotRows = Effect.fn("ProjectionStore.readShellSnapshotRows")(function* (
       options: ShellSnapshotOptions | undefined,
     ) {
-      const targetThreadRows = yield* selectShellThreadRows(undefined, options);
+      const worktreeKey =
+        options?.worktreePath === undefined
+          ? undefined
+          : normalizeProjectPathForComparison(options.worktreePath);
+      const targetThreadRows = (yield* selectShellThreadRows(undefined, options)).filter(
+        (row) =>
+          worktreeKey === undefined ||
+          (row.worktree_path !== null &&
+            normalizeProjectPathForComparison(row.worktree_path) === worktreeKey),
+      );
       const targetThreadIds = new Set(targetThreadRows.map((row) => ThreadId.make(row.thread_id)));
       const rowsByThreadId = new Map(
         targetThreadRows.map((row) => [ThreadId.make(row.thread_id), row] as const),
diff --git a/apps/web/src/hooks/useThreadActions.permissions.test.ts b/apps/web/src/hooks/useThreadActions.permissions.test.ts
index 58bc33cd0d645..9496f1cf68b85 100644
--- a/apps/web/src/hooks/useThreadActions.permissions.test.ts
+++ b/apps/web/src/hooks/useThreadActions.permissions.test.ts
@@ -33,7 +33,12 @@ const state = vi.hoisted(() => ({
     projectId: ProjectId;
     title: string;
     worktreePath: string | null;
-    lineage: { parentThreadId: ThreadId | null; sideChat?: boolean };
+    lineage: {
+      parentThreadId: ThreadId | null;
+      relationshipToParent: "fork" | null;
+      rootThreadId: ThreadId;
+      sideChat?: boolean;
+    };
     session: { status: "ready" | "stopped" } | null;
     latestTurn: null;
   }[],
@@ -265,7 +270,7 @@ beforeEach(() => {
       projectId: ProjectId.make("project"),
       title: "Thread",
       worktreePath: null,
-      lineage: { parentThreadId: null },
+      lineage: { parentThreadId: null, relationshipToParent: null, rootThreadId: target.threadId },
       session: null,
       latestTurn: null,
     },
@@ -420,6 +425,32 @@ describe("thread action permissions", () => {
     expect(threadPanelStatePresence(target)).toEqual(panelStateCleared);
   });
 
+  it("offers to delete the worktree that only its side chats share", async () => {
+    state.scopes
+      .get(secondary)!
+      .add(AuthOrchestrationOperateScope)
+      .add(AuthSourceControlWriteScope);
+    state.threads[0]!.worktreePath = "/worktrees/thread";
+    state.threads.push({
+      ...state.threads[0]!,
+      id: ThreadId.make("side-chat"),
+      lineage: {
+        parentThreadId: target.threadId,
+        relationshipToParent: "fork",
+        rootThreadId: target.threadId,
+        sideChat: true,
+      },
+    });
+    expect((await useThreadActions().deleteThread(target))._tag).toBe("Success");
+    expect(state.confirm).toHaveBeenCalledOnce();
+    expect(state.requests.map((request) => request.action)).toEqual([
+      "stopSession",
+      "delete",
+      "removeWorktree",
+      "refreshStatus",
+    ]);
+  });
+
   it("clears the drafts of the side chats deleted with it", async () => {
     state.scopes.get(secondary)!.add(AuthOrchestrationOperateScope);
     const parent = state.threads[0]!;
@@ -427,9 +458,13 @@ describe("thread action permissions", () => {
       {
         ...parent,
         id: ThreadId.make("side-chat"),
-        lineage: { parentThreadId: parent.id, sideChat: true },
+        lineage: { ...parent.lineage, parentThreadId: parent.id, sideChat: true },
+      },
+      {
+        ...parent,
+        id: ThreadId.make("fork"),
+        lineage: { ...parent.lineage, parentThreadId: parent.id },
       },
-      { ...parent, id: ThreadId.make("fork"), lineage: { parentThreadId: parent.id } },
     );
     expect((await useThreadActions().deleteThread(target))._tag).toBe("Success");
     expect(state.localEffects).toEqual(
diff --git a/apps/web/src/hooks/useThreadActions.ts b/apps/web/src/hooks/useThreadActions.ts
index e91f170689a56..413130f507272 100644
--- a/apps/web/src/hooks/useThreadActions.ts
+++ b/apps/web/src/hooks/useThreadActions.ts
@@ -500,10 +500,16 @@ export function useThreadActions() {
             }),
           )
         : undefined;
-    const survivingThreads =
-      deletedIds && deletedIds.size > 0
-        ? threads.filter((entry) => entry.id === threadRef.threadId || !deletedIds.has(entry.id))
-        : threads;
+    // Deleting a thread also deletes its side chats, which share its worktree.
+    const removedIds = new Set<ThreadId>(deletedIds);
+    for (const entry of threads) {
+      if (entry.lineage.sideChat === true && entry.lineage.parentThreadId === threadRef.threadId) {
+        removedIds.add(entry.id);
+      }
+    }
+    const survivingThreads = threads.filter(
+      (entry) => entry.id === threadRef.threadId || !removedIds.has(entry.id),
+    );
     const environmentConfig = appAtomRegistry
       .get(environmentServerConfigsAtom)
       .get(threadRef.environmentId);
@@ -521,7 +527,7 @@ export function useThreadActions() {
       if (
         occupants._tag !== "Success" ||
         occupants.value.threadIds.some(
-          (threadId) => threadId !== threadRef.threadId && deletedIds?.has(threadId) !== true,
+          (threadId) => threadId !== threadRef.threadId && !removedIds.has(threadId),
         )
       ) {
         orphanedWorktreePath = null;