fix(init): honor piped y/n for 'init --here', error only on no-input

Per maintainer review: restore the second-revision shape. Calling
typer.confirm normally keeps 'echo y | specify init --here' reaching the
non-destructive preserve-merge path (and piped 'n' cancels with exit 0).
Only when no confirmation input is available at all (closed/empty stdin
-> typer.Abort/EOFError) is it converted into the actionable error that
points at --force. This drops the _stdin_is_interactive fail-fast that
broke the common piped-confirm idiom and made preserve-merge
interactive-only. The preserve test no longer needs to monkeypatch
_stdin_is_interactive - it passes on the real contract.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: jawwad-ali

src/specify_cli/commands/init.py

@@ -228,28 +228,25 @@ def init(
                     console.print(
                         "[cyan]--force supplied: skipping confirmation and proceeding with merge[/cyan]"
                     )
-                elif not _stdin_is_interactive():
-                    # No interactive terminal: do NOT prompt. A non-TTY stdin that
-                    # is open but idle (a common CI/agent scenario) would block on
-                    # typer.confirm, so fail fast and require an explicit --force
-                    # for a non-interactive merge. No merge happens here, so no
-                    # merge/overwrite warning is printed.
-                    console.print(
-                        "[red]Error:[/red] Current directory is not empty and no "
-                        "interactive terminal is available to confirm. Re-run with "
-                        "[bold]--force[/bold] to merge into it."
-                    )
-                    raise typer.Exit(1)
                 else:
                     console.print(
                         "[yellow]Template files will be merged with existing content and may overwrite existing files[/yellow]"
                     )
+                    # Call typer.confirm normally so piped y/n is honored — e.g.
+                    # `echo y | specify init --here` keeps reaching the
+                    # non-destructive preserve-merge path. Only when no
+                    # confirmation input is available at all (closed/empty stdin
+                    # → EOF/Abort) do we convert it into an actionable error that
+                    # points at --force, rather than blocking or failing opaquely.
                     try:
                         proceed = typer.confirm("Do you want to continue?")
-                    except typer.Abort:
-                        # Interactive cancel (e.g. Ctrl+C): a normal cancellation.
-                        console.print("[yellow]Operation cancelled[/yellow]")
-                        raise typer.Exit(0) from None
+                    except (typer.Abort, EOFError):
+                        console.print(
+                            "[red]Error:[/red] Current directory is not empty and no "
+                            "confirmation input is available. Re-run with "
+                            "[bold]--force[/bold] to merge into it."
+                        )
+                        raise typer.Exit(1) from None
                     if not proceed:
                         console.print("[yellow]Operation cancelled[/yellow]")
                         raise typer.Exit(0)

tests/integrations/test_cli.py

@@ -860,17 +860,11 @@ def test_init_here_force_overwrites_shared_infra(self, tmp_path):
         # --force should overwrite the custom file
         assert (scripts_dir / "common.sh").read_text(encoding="utf-8") != custom_content
 
-    def test_init_here_without_force_preserves_shared_infra(self, tmp_path, monkeypatch):
-        """E2E: confirming the merge interactively (no --force) preserves existing
-        shared infra files (unlike --force, which overwrites them)."""
+    def test_init_here_without_force_preserves_shared_infra(self, tmp_path):
+        """E2E: confirming the merge with piped "y" (no --force) preserves
+        existing shared infra files (unlike --force, which overwrites them)."""
         from typer.testing import CliRunner
         from specify_cli import app
-        from specify_cli.commands import init as init_mod
-
-        # Simulate an interactive terminal so the confirmation prompt is reached;
-        # the piped "y" then exercises the preserve-merge path. (Non-interactive
-        # sessions now fail fast and require --force.)
-        monkeypatch.setattr(init_mod, "_stdin_is_interactive", lambda: True)
 
         project = tmp_path / "e2e-no-force"
         project.mkdir()