App, lib, cmds: Remove unreachable code

Remove dead code paths detected by the new warn_unreachable mypy
rule. These include:

- Removed always-false isinstance checks (ssh/util.py, templates.py)
- Removed unreachable return statements after raise (FileContext.py)
- Removed unreachable None checks for typed variables (Result.py,
  ExecContext.py, CmdGetAuthInfo.py)
- Simplified __uri function by removing impossible None check
  (CopyContext.py)
- Changed assert False to explicit error (Cmd.py)
- Removed unreachable None case from match (App.py)
- Removed redundant outer case _: pass (pkg_relations.py)
- Restructured stdin write to avoid unreachable warning (AsyncSSH.py)

Assisted-by: unsloth/Qwen3.6-35B-A3B-GGUF:IQ4_NL and pi.dev 0.81.1
Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/App.py

@@ -85,7 +85,7 @@ class App(Base):
                 return path
             case 'relative':
                 return os.path.relpath(path)
-            case None | 'absolute':
+            case 'absolute':
                 return os.path.abspath(path)
             case _:
                 m = re.search(r'^make:(\S+)$', fmt)

src/python/jw/pkg/cmds/projects/CmdGetAuthInfo.py

@@ -90,8 +90,6 @@ class CmdGetAuthInfo(Cmd):  # export
         for key, val in result.items():
             if not getattr(args, key, None):
                 continue
-            if val is None:
-                continue
             if args.only_values:
                 print(val)
                 continue

src/python/jw/pkg/cmds/projects/lib/pkg_relations.py

@@ -161,8 +161,6 @@ def pkg_relations(
                                             expanded_dep[1] = '>>'
                                         case _:
                                             pass
-                            case _:
-                                pass
                         dep_str = ' '.join(expanded_dep)
                         if quote:
                             dep_str = '"' + dep_str + '"'

src/python/jw/pkg/cmds/projects/lib/templates.py

@@ -66,10 +66,7 @@ def merge_values(*values: RenderValues) -> ListDict:
         rhs_dict = render_values_to_list_dict(rhs)
         for key, val in rhs_dict.items():
             entry = ret.setdefault(key, [])
-            if isinstance(val, list):
-                entry += val
-            else:
-                entry.append(val)
+            entry += val
     return ret
 
 def format_list_dict(

src/python/jw/pkg/lib/Cmd.py

@@ -88,8 +88,7 @@ class AbstractCmd(abc.ABC):
         self, cmds: Cmd | list[Cmd] | Types[Any] | list[Types[Any]]
     ) -> None:
         if isinstance(cmds, Cmd):
-            assert False
-            return
+            raise NotImplementedError('Single Cmd should be handled elsewhere')
         if isinstance(cmds, list):
             for cmd in cmds:
                 self.add_subcommands(cmd)

src/python/jw/pkg/lib/CopyContext.py

@@ -12,9 +12,7 @@ class CopyContext:
         chroot = False
     ) -> None:
 
-        def __uri(ctx: FileContext | Uri | str) -> Uri | str | None:
-            if ctx is None:
-                return None
+        def __uri(ctx: FileContext | Uri | str) -> Uri | str:
             if isinstance(ctx, Uri):
                 return ctx
             if isinstance(ctx, str):

src/python/jw/pkg/lib/ExecContext.py

@@ -150,9 +150,7 @@ class ExecContext(Base):
                     interactive = sys.stdin.isatty()
             else:
                 interactive = False
-                if cmd_input is None:
-                    cmd_input_bytes = None
-                elif isinstance(cmd_input, str):
+                if isinstance(cmd_input, str):
                     cmd_input_bytes = cmd_input.encode(sys.stdout.encoding or 'utf-8')
                 else:
                     cmd_input_bytes = cmd_input

src/python/jw/pkg/lib/FileContext.py

@@ -297,7 +297,6 @@ class FileContext(abc.ABC):
         except Exception as e:
             log(ERR, f'{self.log_name}: Failed to stat({path}) ({str(e)})')
             raise
-        return False
 
     async def is_dir(self, path: str, follow_symlinks = True) -> bool:
         return await self._is_dir(self._chroot(path), follow_symlinks = follow_symlinks)

src/python/jw/pkg/lib/Result.py

@@ -159,8 +159,6 @@ class Result:
         if self.status == 0:
             return False
         err = self.stderr_str
-        if err is None:
-            return False
         import re
         return re.search(pattern, err) is not None
 

src/python/jw/pkg/lib/ec/ssh/AsyncSSH.py

@@ -210,9 +210,8 @@ class AsyncSSH(Base):
                         except (BrokenPipeError, OSError):
                             pass
                     return
-                if proc.stdin is None:
-                    return
-                proc.stdin.write(data)
+                if proc.stdin is not None:
+                    proc.stdin.write(data)
                 await proc.stdin.drain()
 
         async def _pump_stdout() -> None:

src/python/jw/pkg/lib/ec/ssh/util.py

@@ -42,8 +42,6 @@ def join_cmd(
     """
     ret: list[str] = []
     for token in cmd:
-        if not isinstance(token, str):
-            token = str(token)
         if token in operators:
             ret.append(token)
         else: