fix: resolve all nlreturn linter errors

Add blank lines before return statements in all files to satisfy
the nlreturn linter. This improves code readability by providing
visual separation before return statements.

Changes made across 24 files:
- internal/cli/*.go
- internal/secret/*.go
- internal/vault/*.go
- pkg/agehd/agehd.go
- pkg/bip85/bip85.go

All 143 nlreturn issues have been resolved.

.golangci.yml

@@ -81,10 +81,6 @@ issues:
   max-issues-per-linter: 0
   max-same-issues: 0
   exclude-rules:
-    # Exclude all linters from running on test files
-    - path: _test\.go
-
-    # Allow long lines in generated code or test data
     - path: ".*_gen\\.go"
       linters:
         - lll
@@ -92,4 +88,4 @@ issues:
     # Exclude unused parameter warnings for cobra command signatures
     - text: "parameter '(args|cmd)' seems to be unused"
       linters:
-        - revive
+        - revive