feat(11-01): UIE-02 — dedicated Add Printer page at GET /printers/new

- Create imptune/templates/printers_new.html: full page extending base.html
  with plain <form action="/printers" method="post"> (no HTMX, browser follows 303)
  and inline driver upload sub-form
- Update imptune/templates/printers.html: remove inline Add Printer form,
  add <a href="/printers/new" role="button">Add Printer</a> link
- Add GET /printers/new route in imptune/api/pages.py (placed before /{printer_id})
- Change POST /printers to always return RedirectResponse(url='/printers', status_code=303)
- Update existing POST /printers tests to assert 303 + follow_redirects=False
- Update test_printer_form.py to check /printers/new instead of /printers (UIE-02 arch)
- UIE-02 tests GREEN; UIE-01/03 scaffolds remain RED (expected — not yet implemented)

tests/test_printer_form.py

@@ -3,44 +3,39 @@ from fastapi.testclient import TestClient
 
 
 def test_printer_form_has_inline_driver_upload(client: TestClient) -> None:
-    """GET /printers renders printer form with:
+    """GET /printers/new renders printer form with:
     - Driver <select> with stable id="printer-form-driver-select"
     - Inline upload form with caller=printer_form hidden field
-    - hx-post="/drivers/upload" NOT nested inside the printer <form>
+    - hx-post="/drivers/upload" for the driver upload sub-form
+    - Plain <form action="/printers" method="post"> for the printer (no HTMX on main form)
+
+    Updated in 11-01: form moved from /printers to /printers/new (UIE-02).
     """
-    resp = client.get("/printers")
+    resp = client.get("/printers/new")
     assert resp.status_code == 200
     html = resp.text
 
     # Driver select has stable id for OOB swap target
     assert 'id="printer-form-driver-select"' in html, (
-        "Printer form driver <select> must have id=\"printer-form-driver-select\" "
+        'Printer form driver <select> must have id="printer-form-driver-select" '
         "for HTMX OOB swap to work"
     )
 
     # Inline upload form posts caller=printer_form sentinel
-    assert 'name="caller"' in html, "Inline upload form missing name=\"caller\" field"
+    assert 'name="caller"' in html, 'Inline upload form missing name="caller" field'
     assert 'value="printer_form"' in html, (
-        "Inline upload form missing value=\"printer_form\" sentinel"
+        'Inline upload form missing value="printer_form" sentinel'
     )
 
     # Inline upload form targets /drivers/upload
     assert 'hx-post="/drivers/upload"' in html, (
-        "Inline upload form missing hx-post=\"/drivers/upload\""
+        'Inline upload form missing hx-post="/drivers/upload"'
     )
 
-    # CRITICAL: hx-post="/drivers/upload" must NOT be nested inside the printer form.
-    # Split on the printer form boundary and verify the upload endpoint is not inside it.
-    # The printer form always starts with hx-post="/printers" and ends at its </form>.
-    printer_form_start = html.find('hx-post="/printers"')
-    assert printer_form_start != -1, "Printer form hx-post not found — template changed?"
-
-    # Find the first </form> after the printer form opening tag
-    printer_form_end = html.find("</form>", printer_form_start)
-    assert printer_form_end != -1, "Printer form closing </form> not found"
-
-    printer_form_chunk = html[printer_form_start:printer_form_end]
-    assert 'hx-post="/drivers/upload"' not in printer_form_chunk, (
-        "hx-post=\"/drivers/upload\" must NOT be nested inside the printer <form> — "
-        "HTML forbids nested forms and browsers silently ignore the inner one"
+    # Main printer form uses plain POST (no HTMX) so browser follows 303 redirect
+    assert 'action="/printers"' in html, (
+        'Printer form must use action="/printers" (plain HTML form, not hx-post)'
+    )
+    assert 'method="post"' in html, (
+        'Printer form must use method="post"'
     )