diff --git a/examples/research-shelf.el b/examples/research-shelf.el
index 0e541e0..eda6da5 100644
--- a/examples/research-shelf.el
+++ b/examples/research-shelf.el
@@ -336,13 +336,24 @@ constructed.  When omitted, initialize it for direct programmatic callers."
      (append (list :id (plist-get row :id)) fields)
      message)))
 
-;; Named Actions keep product mutations out of View callbacks.  The View layer
-;; only dispatches these stable application commands with the current model.
-(etaf-action-define etaf-research-shelf-filter (runtime model filter)
-  "Apply FILTER to MODEL."
-  (ignore runtime)
-  (etaf-research-shelf--set-filter model filter))
+(defun etaf-research-shelf--advance-item (model item)
+  "Advance ITEM in MODEL by ten percent without changing selection."
+  (let ((next (min 100 (+ 10 (or (plist-get item :progress) 0)))))
+    (etaf-research-shelf--mutate
+     model 'update
+     (list :id (plist-get item :id) :progress next
+           :status (if (= next 100) "finished" "reading") :updated "Just now")
+     "✓ Progress saved")))
 
+(defun etaf-research-shelf--star-item (model item starred)
+  "Set ITEM's STARRED value in MODEL without changing selection."
+  (etaf-research-shelf--mutate
+   model 'update
+   (list :id (plist-get item :id) :starred (if starred 1 0) :updated "Just now")
+   (if starred "★ Starred locally" "Removed star")))
+
+;; Named Actions expose reusable application commands.  Simple local controls
+;; can call ordinary business functions directly, as the filter button does.
 (etaf-action-define etaf-research-shelf-reload (runtime model)
   "Reload MODEL's data source."
   (ignore runtime)
@@ -367,13 +378,8 @@ constructed.  When omitted, initialize it for direct programmatic callers."
 (etaf-action-define etaf-research-shelf-progress (runtime model)
   "Advance the selected reading by ten percent."
   (ignore runtime)
-  (when-let* ((current (etaf-research-shelf--selected model))
-              (value (or (plist-get current :progress) 0)))
-    (etaf-research-shelf--update-selected
-     model (list :progress (min 100 (+ value 10))
-                 :status (if (>= (+ value 10) 100) "finished" "reading")
-                 :updated "Just now")
-     "✓ Progress saved")))
+  (when-let* ((current (etaf-research-shelf--selected model)))
+    (etaf-research-shelf--advance-item model current)))
 
 (etaf-action-define etaf-research-shelf-finish (runtime model)
   "Mark the selected reading finished."
@@ -386,10 +392,8 @@ constructed.  When omitted, initialize it for direct programmatic callers."
   "Toggle the selected reading's star."
   (ignore runtime)
   (when-let* ((current (etaf-research-shelf--selected model)))
-    (let ((starred (= 1 (or (plist-get current :starred) 0))))
-      (etaf-research-shelf--update-selected
-       model (list :starred (if starred 0 1) :updated "Just now")
-       (if starred "Removed star" "★ Starred locally")))))
+    (etaf-research-shelf--star-item
+     model current (not (= 1 (or (plist-get current :starred) 0))))))
 
 (etaf-action-define etaf-research-shelf-archive (runtime model)
   "Archive the selected reading."
@@ -401,12 +405,55 @@ constructed.  When omitted, initialize it for direct programmatic callers."
 ;;; VIEW / COMPONENTS / COMPOSITION
 ;;; ---------------------------------------------------------------------------
 
+(etaf-define-component etaf-research-shelf-item-star (&key item)
+  "Star ITEM through the consuming App's model."
+  :setup
+  (etaf-inject 'research-shelf-model nil t)
+  :render
+  (let ((model (etaf-state))
+        (record item))
+    (etaf-view
+     (etaf-checkbox
+      :label "★" :aria-label "Star reading"
+      :checked (= 1 (or (plist-get record :starred) 0))
+      :on-change
+      (lambda (next)
+        (etaf-research-shelf--star-item model record next))))))
+
+(etaf-define-component etaf-research-shelf-item-advance (&key item)
+  "Advance ITEM through the consuming App's model."
+  :setup
+  (etaf-inject 'research-shelf-model nil t)
+  :render
+  (let ((model (etaf-state))
+        (record item))
+    (etaf-view
+     (etaf-button
+      :label "+10%" :aria-label "Advance reading" :variant 'ghost
+      :disabled
+      (or (not (null (member (plist-get record :status) '("finished" "archived"))))
+          (>= (or (plist-get record :progress) 0) 100))
+      :on-press
+      (lambda () (etaf-research-shelf--advance-item model record))))))
+
+(defun etaf-research-shelf-star-cell (row)
+  "Return ROW's star control at the consuming list's Context."
+  (etaf-view (etaf-research-shelf-item-star :item row)))
+
+(defun etaf-research-shelf-advance-cell (row)
+  "Return ROW's progress control at the consuming list's Context."
+  (etaf-view (etaf-research-shelf-item-advance :item row)))
+
 (defconst etaf-research-shelf--grid-columns
   '((:key :title :label "Title" :width 21)
     (:key :author :label "Author" :width 12)
     (:key :status :label "Status" :width 10)
     (:key :progress :label "Progress" :width 8)
-    (:key :kind :label "Kind" :width 7))
+    (:key :kind :label "Kind" :width 7)
+    (:key :starred :label "Star" :width 6
+     :cell etaf-research-shelf-star-cell)
+    (:key :advance :label "Advance" :width 8
+     :cell etaf-research-shelf-advance-cell))
   "Compact DataGrid columns for the Research Shelf list.")
 
 (defun etaf-research-shelf--status-label (status)
@@ -438,27 +485,20 @@ constructed.  When omitted, initialize it for direct programmatic callers."
   :setup
   (list :model (etaf-inject 'research-shelf-model nil t)
         :form (etaf-inject 'research-shelf-filters nil t))
-  :view
-  (etaf-button
-   :label
-   (let* ((model (plist-get (etaf-state) :model))
-          (form (plist-get (etaf-state) :form))
-          (label (etaf-research-shelf--filter-label
-                  form filter-key fallback)))
-     (if (eq filter-key (etaf-value (plist-get model :filter)))
-         (concat "● " label)
-       label))
-   :variant
-   (if (eq filter-key
-           (etaf-value
-            (plist-get (plist-get (etaf-state) :model) :filter)))
-       'secondary
-     'ghost)
-   :on-press
-   (let ((model (plist-get (etaf-state) :model))
-         (key filter-key))
-     (lambda ()
-       (etaf-dispatch 'etaf-research-shelf-filter model key)))))
+  :render
+  (let* ((state (etaf-state))
+         (model (plist-get state :model))
+         (form (plist-get state :form))
+         (key filter-key)
+         (label (etaf-research-shelf--filter-label form key fallback)))
+    (etaf-view
+     (etaf-button
+      :label (if (eq key (etaf-value (plist-get model :filter)))
+                 (concat "● " label)
+               label)
+      :variant (if (eq key (etaf-value (plist-get model :filter)))
+                   'secondary 'ghost)
+      :on-press (lambda () (etaf-research-shelf--set-filter model key))))))
 
 (etaf-define-component etaf-research-shelf-filter-rail ()
   "Render the Research Shelf filter rail from inherited Context."
diff --git a/tests/research-shelf-cell-tests.el b/tests/research-shelf-cell-tests.el
new file mode 100644
index 0000000..a37e7bb
--- /dev/null
+++ b/tests/research-shelf-cell-tests.el
@@ -0,0 +1,278 @@
+;;; research-shelf-cell-tests.el --- SQLite editing cell acceptance -*- lexical-binding: t; -*-
+
+;;; Commentary:
+
+;; Mount the real 256-record application through its public root.  UI events
+;; drive edits; independent SQLite reads prove persistence.  Runtime internals
+;; are inspected only to obtain the example-owned model for invariant checks.
+
+;;; Code:
+
+(require 'cl-lib)
+(require 'ert)
+(require 'etaf-research-shelf
+         (expand-file-name "../examples/research-shelf.el"
+                           (file-name-directory
+                            (or load-file-name
+                                (bound-and-true-p byte-compile-current-file)
+                                buffer-file-name))))
+
+(defun research-cell-test--mount (buffer database-file)
+  "Mount a fresh Research App in BUFFER backed by DATABASE-FILE."
+  (let ((etaf-research-shelf-database-file database-file)
+        (etaf-research-shelf-fixture-size 256)
+        (etaf-research-shelf-page-size 12))
+    (etaf-mount
+     buffer
+     (etaf-research-shelf-root
+      (etaf-playground-read-static "research-shelf")
+      (etaf-playground-read-ecss "research-shelf"))
+     '(:viewport-width 1400 :viewport-height 80))
+    (etaf-runtime-for-buffer buffer)))
+
+(defun research-cell-test--model (runtime)
+  "Return the sole reading list's application model in RUNTIME."
+  (let ((instances
+         (cl-remove-if-not
+          (lambda (instance)
+            (eq 'etaf-research-shelf-reading-list
+                (etaf--component-spec-name
+                 (etaf--component-instance-spec instance))))
+          (hash-table-values (etaf-runtime-instances runtime)))))
+    (should (= (length instances) 1))
+    (plist-get (etaf--component-instance-state (car instances)) :model)))
+
+(defun research-cell-test--control (runtime identity label)
+  "Find the control with LABEL in RUNTIME's row with IDENTITY."
+  (let* ((row (intern (format "research-shelf-row-%d" identity)))
+         (row-id (car (gethash row (etaf-runtime-host-ancestries
+                                  runtime (list row)))))
+         (entries
+          (cl-remove-if-not
+           (lambda (entry) (equal label (plist-get (cdr entry) :aria-label)))
+           (etaf-runtime-host-props-entries runtime)))
+         (ancestries (etaf-runtime-host-ancestries runtime (mapcar #'car entries))))
+    (should row-id)
+    (setq entries
+          (cl-remove-if-not
+           (lambda (entry) (memq row-id (gethash (car entry) ancestries)))
+           entries))
+    (should (= (length entries) 1))
+    (caar entries)))
+
+(defun research-cell-test--press (runtime identity label)
+  "Press the control with LABEL in RUNTIME's row with IDENTITY."
+  (etaf-dispatch-event
+   runtime (research-cell-test--control runtime identity label) 'press))
+
+(defun research-cell-test--row (database-file identity)
+  "Read IDENTITY from DATABASE-FILE through an independent SQLite source."
+  (let* ((etaf-research-shelf-database-file database-file)
+         (source (etaf-sqlite-source (etaf-research-shelf--database))))
+    (car (plist-get (etaf-data-source-load-page source (list :id identity) 1 1)
+                    :items))))
+
+(defun research-cell-test--text (runtime &optional ref)
+  "Return RUNTIME's displayed text, restricted to REF when supplied."
+  (with-current-buffer (etaf-runtime-buffer runtime)
+    (let ((bounds (and ref (etaf-host-ref-bounds runtime ref))))
+      (when ref (should bounds))
+      (buffer-substring-no-properties
+       (if bounds (car bounds) (point-min))
+       (if bounds (cdr bounds) (point-max))))))
+
+(cl-defmacro research-cell-test--with-app ((runtime database-file) &rest body)
+  "Mount RUNTIME using a temporary DATABASE-FILE, then run BODY and clean up."
+  (declare (indent 1))
+  `(let ((,database-file (make-temp-file "research-cell-" nil ".sqlite")))
+     (unwind-protect
+         (with-temp-buffer
+           (let ((,runtime (research-cell-test--mount (current-buffer)
+                                                    ,database-file)))
+             (unwind-protect (progn ,@body)
+               (etaf-unmount ,runtime))))
+       (delete-file ,database-file))))
+
+(ert-deftest research-shelf-cell-edits-persist-without-selecting-the-row ()
+  "Controlled cells share SQLite updates with detail actions, not selection."
+  (research-cell-test--with-app (runtime database-file)
+    (let* ((model (research-cell-test--model runtime))
+           (data (etaf-research-shelf--controller model)))
+      (should (= (etaf-value (etaf-data-total data)) 256))
+      (should (= (etaf-value (etaf-data-page-size data)) 12))
+      (should (= (length (etaf-value (etaf-data-items data))) 12))
+      (etaf-dispatch-event runtime 'research-shelf-row-1 'press)
+      (let ((star (research-cell-test--control runtime 2 "Star reading")))
+        (should (string-match-p "☐" (research-cell-test--text runtime star)))
+        (research-cell-test--press runtime 2 "Star reading")
+        (should (= (plist-get (research-cell-test--row database-file 2) :starred) 1))
+        (should (equal star (research-cell-test--control runtime 2 "Star reading")))
+        (should (string-match-p "☑" (research-cell-test--text runtime star)))
+        (research-cell-test--press runtime 2 "Star reading")
+        (should (= (plist-get (research-cell-test--row database-file 2) :starred) 0)))
+      (research-cell-test--press runtime 2 "Advance reading")
+      (should (= (plist-get (research-cell-test--row database-file 2) :progress) 10))
+      (should (equal (plist-get (research-cell-test--row database-file 2) :status)
+                     "reading"))
+      (should (equal (etaf-value (etaf-data-selection data)) '(1)))
+      (should (equal (plist-get (etaf-data-selected-item data) :title)
+                     "The Shape of Tools"))
+      ;; A detail edit must refresh the same controlled cell's current props.
+      (etaf-dispatch-event runtime 'research-shelf-row-2 'press)
+      (etaf-dispatch-event runtime 'research-shelf-star 'press)
+      (should (string-match-p
+               "☑" (research-cell-test--text
+                    runtime (research-cell-test--control runtime 2 "Star reading"))))
+      (etaf-dispatch-event runtime 'research-shelf-finish 'press)
+      (let ((advance (research-cell-test--control runtime 2 "Advance reading")))
+        (should (plist-get (etaf-runtime-host-props-for runtime advance) :disabled))
+        (should-error (etaf-dispatch-event runtime advance 'press)
+                      :type 'etaf-event-error)
+        (should (= (plist-get (research-cell-test--row database-file 2) :progress) 100)))
+      (etaf-dispatch-event runtime 'research-shelf-row-1 'press)
+      (etaf-dispatch-event runtime 'research-shelf-archive 'press)
+      (should (plist-get
+               (etaf-runtime-host-props-for
+                runtime (research-cell-test--control runtime 1 "Advance reading"))
+               :disabled)))))
+
+(ert-deftest research-shelf-edit-controls-have-distinct-column-owners ()
+  "Star and advance controls belong to separate stable Table columns."
+  (research-cell-test--with-app (runtime database-file)
+    (ignore database-file)
+    (let* ((entries (etaf-runtime-host-props-entries runtime))
+           (ancestries
+            (etaf-runtime-host-ancestries runtime (mapcar #'car entries))))
+      (dolist (expected '(("Star reading" . :starred)
+                          ("Advance reading" . :advance)))
+        (let* ((control (research-cell-test--control runtime 2 (car expected)))
+               (chain (gethash control ancestries))
+               (cell
+                (cl-find-if
+                 (lambda (entry)
+                   (and (member "etaf-table-cell"
+                                (split-string (or (plist-get (cdr entry) :class) "")))
+                        (memq (car (gethash (car entry) ancestries)) chain)))
+                 entries)))
+          (should cell)
+          (should (eq (cdr expected) (plist-get (cdr cell) :key))))))))
+
+(ert-deftest research-shelf-cells-follow-filter-page-and-theme ()
+  "Filtered removal and paging recreate cells with current SQLite values."
+  (research-cell-test--with-app (runtime database-file)
+    (let* ((data (etaf-research-shelf--controller
+                  (research-cell-test--model runtime))))
+      (etaf-dispatch-event runtime 'research-shelf-filter-starred 'press)
+      (should (= (etaf-value (etaf-data-total data)) 54))
+      (let ((old-star (research-cell-test--control runtime 1 "Star reading")))
+        (research-cell-test--press runtime 1 "Star reading")
+        (should (= (etaf-value (etaf-data-total data)) 53))
+        (should-not (etaf-runtime-host-props-for runtime 'research-shelf-row-1))
+        (should-not (etaf-runtime-host-props-for runtime old-star)))
+      (etaf-dispatch-event runtime 'research-shelf-theme-toggle 'press)
+      (dolist (item (etaf-value (etaf-data-items data)))
+        (should (string-match-p
+                 "☑" (research-cell-test--text
+                      runtime (research-cell-test--control
+                               runtime (plist-get item :id) "Star reading")))))
+      (etaf-dispatch-event runtime 'research-shelf-filter-all 'press)
+      (should (= (etaf-value (etaf-data-total data)) 256))
+      (should (string-match-p
+               "☐" (research-cell-test--text
+                    runtime (research-cell-test--control runtime 1 "Star reading"))))
+      (etaf-dispatch-event runtime 'research-shelf-page-next 'press)
+      (should (equal (mapcar #'etaf-research-shelf--item-id
+                             (etaf-value (etaf-data-items data)))
+                     (number-sequence 13 24)))
+      (research-cell-test--press runtime 13 "Star reading")
+      (research-cell-test--press runtime 13 "Advance reading")
+      (should (= (plist-get (research-cell-test--row database-file 13) :progress) 52))
+      (etaf-dispatch-event runtime 'research-shelf-page-previous 'press)
+      (should (string-match-p
+               "☐" (research-cell-test--text
+                    runtime (research-cell-test--control runtime 1 "Star reading"))))
+      (etaf-dispatch-event runtime 'research-shelf-page-next 'press)
+      (etaf-dispatch-event runtime 'research-shelf-theme-toggle 'press)
+      (should (string-match-p
+               "☑" (research-cell-test--text
+                    runtime (research-cell-test--control runtime 13 "Star reading"))))
+      (research-cell-test--press runtime 13 "Advance reading")
+      (should (= (plist-get (research-cell-test--row database-file 13) :progress) 62)))))
+
+(ert-deftest research-shelf-cell-sqlite-abort-reloads-the-controlled-value ()
+  "A real SQLite abort preserves the record; Reload restores editable cells."
+  (research-cell-test--with-app (runtime database-file)
+    (let ((before (research-cell-test--row database-file 2))
+          (connection (sqlite-open database-file)))
+      (unwind-protect
+          (progn
+            (sqlite-execute
+             connection
+             "CREATE TRIGGER reject_cell_edit BEFORE UPDATE ON reading_items
+              WHEN NEW.id = 2 BEGIN SELECT RAISE(ABORT, 'cell write rejected'); END")
+            (research-cell-test--press runtime 2 "Star reading")
+            (should (equal before (research-cell-test--row database-file 2)))
+            (should (string-match-p "Could not save" (research-cell-test--text runtime)))
+            (should (string-match-p "Use Reload" (research-cell-test--text runtime)))
+            (etaf-dispatch-event runtime 'research-shelf-reload 'press)
+            (should (string-match-p
+                     "☐" (research-cell-test--text
+                          runtime (research-cell-test--control runtime 2 "Star reading"))))
+            (research-cell-test--press runtime 2 "Advance reading")
+            (should (equal before (research-cell-test--row database-file 2)))
+            (should (string-match-p "Could not save" (research-cell-test--text runtime)))
+            (sqlite-execute connection "DROP TRIGGER reject_cell_edit")
+            (etaf-dispatch-event runtime 'research-shelf-reload 'press)
+            (research-cell-test--press runtime 2 "Star reading")
+            (research-cell-test--press runtime 2 "Advance reading")
+            (should (= (plist-get (research-cell-test--row database-file 2) :starred) 1))
+            (should (= (plist-get (research-cell-test--row database-file 2) :progress) 10))
+            (should (string-match-p
+                     "☑" (research-cell-test--text
+                          runtime (research-cell-test--control runtime 2 "Star reading")))))
+        (sqlite-close connection)))))
+
+(ert-deftest research-shelf-cell-component-reuses-across-independent-apps ()
+  "One cell definition resolves each App's own Context, including remounts."
+  (research-cell-test--with-app (left left-file)
+    (research-cell-test--with-app (right right-file)
+      (let ((right-text (research-cell-test--text right))
+            (left-data (etaf-research-shelf--controller
+                        (research-cell-test--model left)))
+            (right-data (etaf-research-shelf--controller
+                         (research-cell-test--model right))))
+        (should-not (eq left-data right-data))
+        (dolist (data (list left-data right-data))
+          (should (= (etaf-value (etaf-data-total data)) 256))
+          (should (= (length (etaf-value (etaf-data-items data))) 12)))
+        (etaf-dispatch-event left 'research-shelf-row-1 'press)
+        (research-cell-test--press left 2 "Star reading")
+        (research-cell-test--press left 2 "Advance reading")
+        (should (equal right-text (research-cell-test--text right)))
+        (should (= (plist-get (research-cell-test--row right-file 2) :starred) 0))
+        (should (= (plist-get (research-cell-test--row right-file 2) :progress) 0))
+        (should (equal (etaf-value (etaf-data-selection left-data)) '(1)))
+        (should-not (etaf-value (etaf-data-selection right-data)))
+        (etaf-dispatch-event right 'research-shelf-theme-toggle 'press)
+        (research-cell-test--press right 1 "Star reading")
+        (should (= (plist-get (research-cell-test--row left-file 1) :starred) 1))
+        (should (= (plist-get (research-cell-test--row right-file 1) :starred) 0))
+        (let ((old-left left)
+              (buffer (etaf-runtime-buffer left)))
+          (etaf-unmount left)
+          (should-not (etaf-runtime-mounted-p old-left))
+          (should-not (etaf-runtime-for-buffer buffer))
+          (research-cell-test--press right 2 "Advance reading")
+          (should (= (plist-get (research-cell-test--row right-file 2) :progress) 10))
+          (setq left (research-cell-test--mount buffer left-file))
+          (should-not (eq left old-left))
+          (should (= (plist-get (research-cell-test--row left-file 2) :progress) 10))
+          (should (string-match-p
+                   "☑" (research-cell-test--text
+                        left (research-cell-test--control left 2 "Star reading"))))
+          (research-cell-test--press left 2 "Advance reading")
+          (should (= (plist-get (research-cell-test--row left-file 2) :progress) 20))
+          (should (= (plist-get (research-cell-test--row right-file 2) :progress) 10)))))))
+
+(provide 'research-shelf-cell-tests)
+;;; research-shelf-cell-tests.el ends here