docs(integrations): document the 'integration list --catalog' flag (#3530)

* docs(integrations): document the 'integration list --catalog' flag

'specify integration list' accepts a --catalog flag (integrations/_query_commands.py:
typer.Option(False, "--catalog", ...)) that browses the full built-in +
community catalog, but the Integrations reference documented no options for the
list command. Add an option table for it, matching the style used by the sibling
'integration search' and 'integration catalog add' sections.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(integrations): clarify that default 'integration list' shows only built-ins

The --catalog row implied the default list already includes the full installed
set; in fact 'integration list' iterates INTEGRATION_REGISTRY (built-ins) and
marks installed status, so a community integration that is not built in only
appears with --catalog. Reword the option and the intro sentence to say the
default shows the built-in integrations and --catalog adds community ones.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: jawwad-ali

docs/reference/integrations.md

@@ -48,7 +48,11 @@ The Specify CLI supports a wide range of AI coding agents. When you run `specify
 specify integration list
 ```
 
-Shows all available integrations, which one is currently installed, and whether each requires a CLI tool or is IDE-based.
+| Option      | Description                                                                                                             |
+| ----------- | ----------------------------------------------------------------------------------------------------------------------- |
+| `--catalog` | Also browse the catalog (built-in **and** community). Community integrations that are not built in are only shown here.  |
+
+Shows the built-in integrations, which one is currently installed, and whether each requires a CLI tool or is IDE-based.
 When multiple integrations are installed, the list marks the default integration separately from the other installed integrations.
 The list also shows whether each built-in integration is declared multi-install safe.