Sheet sets: import statuses, view navigation fields, drawing lock files

Import Layouts as Sheets shows the reference's statuses (already part of
a sheet set / may belong to another sheet set / available) and Browse
replaces the list; the Field dialog SheetView tree lists sheet views with
their properties, scale formats and hyperlinks; drawings open in tabs get
.dwl/.dwl2 lock files that other instances read as open; the codec pin
moves to the revision with sheet views and the default output folder.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Cargo.toml

@@ -91,7 +91,7 @@ block2 = "0.5"
 objc2-foundation = { version = "0.2", features = ["NSArray", "NSURL", "NSString", "NSObject", "NSNotification", "NSThread", "NSEnumerator"] }
 
 [patch."https://github.com/HakanSeven12/opencadcodec.git"]
-opencadcodec = { git = "https://github.com/ramox81/cadcodec.git", rev = "d86f57d" }
+opencadcodec = { git = "https://github.com/ramox81/cadcodec.git", rev = "29aff7e" }
 
 [patch.crates-io]
 iced_core = { git = "https://github.com/iced-rs/iced.git", rev = "23604ff22ab0aad9e00b9327cb7b8546ed84db39" }