Fix interactive mode garbling and login shell PATH conflict

The diff renderer was not invalidated when entering/exiting
interactive mode, causing the cell buffer to get out of sync
when the frame layout changed (different box style, hotkeys).
Force a full redraw on mode transitions.

Also switch from bash -lc to bash -c for subprocess execution.
Login shell initialization can reorder PATH and shadow the
user's preferred PHP binary (e.g. Herd) with a system install.
The subprocess already inherits the correct environment from
the parent process.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aarondfrancis

src/Commands/Concerns/ManagesProcess.php

@@ -170,7 +170,7 @@ protected function buildCommandArray(Screen $screen): array
             'exec ' . $this->command,
         ]);
 
-        return ['bash', '-lc', $built];
+        return ['bash', '-c', $built];
     }
 
     protected function localeEnvironmentVariables(): string

src/Prompt/Dashboard.php

@@ -269,11 +269,13 @@ public function enterInteractiveMode(): void
         }
 
         $this->currentCommand()->setMode(Command::MODE_INTERACTIVE);
+        $this->diffRenderer?->invalidate();
     }
 
     public function exitInteractiveMode(): void
     {
         $this->currentCommand()->setMode(Command::MODE_PASSIVE);
+        $this->diffRenderer?->invalidate();
     }
 
     public function selectTab(int $index): void

tests/Unit/ManagesProcessTest.php

@@ -31,7 +31,7 @@ public function buildWithDimensions(): array
         $result = $command->buildWithDimensions();
 
         $this->assertSame('bash', $result['built'][0]);
-        $this->assertSame('-lc', $result['built'][1]);
+        $this->assertSame('-c', $result['built'][1]);
         $this->assertStringContainsString(
             sprintf('stty cols %d rows %d', $result['width'], $result['height']),
             $result['built'][2]