vt: handle invalid enum before pointer cast in getters

The inline else switch in each C API getter expands the .invalid
case, which has OutType void. When called with .invalid and a null
out pointer, the @ptrCast(@alignCast(out)) panics before getTyped
can return early.

Handle .invalid explicitly in the outer switch of every getter to
short-circuit before the pointer cast. This affects build_info,
cell, row, terminal, osc, and render (three getters).

src/terminal/c/build_info.zig

@@ -43,6 +43,7 @@ pub fn get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| getTyped(
             comptime_data,
             @ptrCast(@alignCast(out)),

src/terminal/c/cell.zig

@@ -110,6 +110,7 @@ pub fn get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| getTyped(
             cell_,
             comptime_data,

src/terminal/c/osc.zig

@@ -76,6 +76,7 @@ pub fn commandData(
     }
 
     return switch (data) {
+        .invalid => false,
         inline else => |comptime_data| commandDataTyped(
             command_,
             comptime_data,

src/terminal/c/render.zig

@@ -193,6 +193,7 @@ pub fn get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| getTyped(
             state_,
             comptime_data,
@@ -467,6 +468,7 @@ pub fn row_cells_get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| rowCellsGetTyped(
             cells_,
             comptime_data,
@@ -566,6 +568,7 @@ pub fn row_get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| rowGetTyped(
             iterator_,
             comptime_data,

src/terminal/c/row.zig

@@ -73,6 +73,7 @@ pub fn get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| getTyped(
             row_,
             comptime_data,

src/terminal/c/terminal.zig

@@ -196,6 +196,7 @@ pub fn get(
     }
 
     return switch (data) {
+        .invalid => .invalid_value,
         inline else => |comptime_data| getTyped(
             terminal_,
             comptime_data,