fix(store-upload): Next/Back/Finish buttons missing .btn base class (#310)

The wizard nav buttons used class="btn-primary" / "btn-secondary"
without the .btn base class, so the padding (10px 20px),
border-radius (8px), font-size, and inline-flex centering rules from
.btn never applied. Buttons rendered as ~18px-tall colored boxes with
no padding (visible mismatch against the sibling Cancel <a> which
correctly used class="btn btn-secondary").

Added .btn to all three buttons (#next-btn, #back-btn, #finish-btn).
No CSS change — purely a markup fix.

Playwright before: next.padding="0px" borderRadius="0px" height=18
Playwright after:  next.padding="10px 20px" borderRadius="8px" height=38

CHANGELOG.md

@@ -10,6 +10,16 @@ CalVer image tags (`stable-YYYY.MM.N`, `dev-YYYY.MM.N`) are produced for every C
 
 ## [Unreleased]
 
+## [0.54.16] — 2026-05-14
+
+### Fixed
+- Store submit-flow wizard buttons were missing the `.btn` base class —
+  Next / Back / Finish on `/store/new` and Save on `/store/edit/<id>`
+  carried only the `.btn-primary` / `.btn-secondary` color modifier, so
+  they rendered with no padding, border-radius, or proper sizing
+  (~18px-tall color boxes) instead of matching their sibling Cancel
+  links. Added the `.btn` base class on all four.
+
 ## [0.54.15] — 2026-05-14
 
 ### Added

app/web/templates/store_edit.html

@@ -163,7 +163,7 @@
     </div>
 
     <div class="actions">
-      <button type="submit" class="btn-primary" id="save-btn"
+      <button type="submit" class="btn btn-primary" id="save-btn"
               {% if pending_sub %}disabled{% endif %}>Save</button>
       <a href="/marketplace/flea/{{ entity.id }}" class="btn btn-secondary">Cancel</a>
     </div>

app/web/templates/store_upload.html

@@ -418,7 +418,7 @@
         </div>
 
         <div class="actions">
-          <button type="button" class="btn-primary" id="next-btn">Next →</button>
+          <button type="button" class="btn btn-primary" id="next-btn">Next →</button>
           <a href="/marketplace?tab=flea" class="btn btn-secondary">Cancel</a>
         </div>
       </div>
@@ -533,8 +533,8 @@
         </div>
 
         <div class="actions">
-          <button type="button" class="btn-primary" id="finish-btn">Finish</button>
-          <button type="button" class="btn-secondary" id="back-btn">← Back</button>
+          <button type="button" class="btn btn-primary" id="finish-btn">Finish</button>
+          <button type="button" class="btn btn-secondary" id="back-btn">← Back</button>
         </div>
       </div>
     </div>

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "agnes-the-ai-analyst"
-version = "0.54.15"
+version = "0.54.16"
 description = "Agnes — AI Data Analyst platform for AI analytical systems"
 requires-python = ">=3.11,<3.14"
 license = "MIT"