feat: configure [backend] loads existing backend config rather than just overwriting it

1 files changed, 23 insertions, 6 deletions

diff --git a/app/ui/tui.py b/app/ui/tui.py
index 83ec43d..95130cf 100644
--- a/app/ui/tui.py
+++ b/app/ui/tui.py
@@ -1113,7 +1113,8 @@ def browse_directory(scr, title: str,
 def checkbox_tree(scr, title: str, families: List[dict],
                   footer: Optional[str] = None,
                   expand_all: bool = False,
-                  back_value: object = None) -> List[Tuple[int, str]]:
+                  back_value: object = None,
+                  checked: Optional[set] = None) -> List[Tuple[int, str]]:
     """Pick model families and packages from an expandable tree.
 
     FAMILIES is a list of dicts (one per family) shaped like::
@@ -1134,9 +1135,12 @@ def checkbox_tree(scr, title: str, families: List[dict],
     cursor. Enter returns the flat list of (family_index, option_key)
     pairs for every checked option, in tree order; at least one checked
     option is required. Nothing is checked by default, and with
-    EXPAND_ALL every family starts expanded. A "[recommended]" tag is
-    shown only when a
-    family has more than one option — a single option needs no tag.
+    EXPAND_ALL every family starts expanded. CHECKED (a set of
+    (family_index, option_key) pairs) pre-checks those options instead,
+    expanding every family that holds a checked option and placing the
+    cursor on the first such family — the "modify an existing config"
+    entry point. A "[recommended]" tag is shown only when a family has
+    more than one option — a single option needs no tag.
     Family and option rows are left-justified like a DOS list. Esc (or
     'q') aborts the wizard unless BACK_VALUE is given (not None), in
     which case either key returns it so the caller can fall back a
@@ -1148,9 +1152,14 @@ def checkbox_tree(scr, title: str, families: List[dict],
                         "Enter = accept  Esc = cancel")
     frame = Frame(scr, title, footer)
     expanded = {index for index in range(len(families))} if expand_all else set()
-    checked = set()  # (family_index, option_key)
+    checked = set(checked or ())  # (family_index, option_key)
 
-    expanded.add(0)
+    if checked:
+        for index, _option_key in checked:
+            expanded.add(index)
+        expanded.add(0)
+    else:
+        expanded.add(0)
 
     def family_checked(index: int) -> bool:
         return any(pair[0] == index for pair in checked)
@@ -1170,9 +1179,17 @@ def checkbox_tree(scr, title: str, families: List[dict],
                     nodes.append(("option", index, option["key"]))
         return nodes
 
+    first_checked = min((index for index, _option_key in checked),
+                        default=None)
     cursor = 0
     while True:
         nodes = visible_nodes()
+        if first_checked is not None:
+            for position, node in enumerate(nodes):
+                if node[0] == "family" and node[1] == first_checked:
+                    cursor = position
+                    break
+            first_checked = None
         cursor = max(0, min(cursor, len(nodes) - 1))
         frame.rows = []
         for node in nodes: