docs: advertise Playbooks as Entry + Enterprise + Enterprise Advanced only (#38532)

* docs: advertise Playbooks as Entry + Enterprise + Enterprise Advanced only

Update the plan-availability badge on every workflow-automation page from `all-commercial` (Entry + Professional + Enterprise + Enterprise Advanced) to `entry-ent` (Entry + Enterprise + Enterprise Advanced; not available on Professional) so that Playbooks is no longer advertised on the Professional plan.

Co-authored-by: Cursor <cursoragent@cursor.com>

* docs: fix duplicate 'plans' rendering in PlanAvailability badge

The badge component appended ' plans' whenever `linkText` did not end with 'plans', to defensively add the noun for slugs that omitted it. All current slugs already contain 'plans'; the `entry-ent` slug ends with '(not available on Professional)', which caused the auto-append to produce the doubled-word output 'Entry, Enterprise, and Enterprise Advanced plans (not available on Professional) plans'.

Switch the check from `endsWith('plans')` to `includes('plans')` so slugs whose linkText contains the noun anywhere skip the auto-append. Behaviour for every other slug is unchanged.

Co-authored-by: Cursor <cursoragent@cursor.com>

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Co-authored-by: Cursor <cursoragent@cursor.com>