Update remote-select prompts to "Type to search …"

[maebeale]

What is the goal of this PR and why is this important?

• Applies the same prompt pattern as Clarify workshop search prompt on StoryIdea form #1509 (which updated the StoryIdea form) to the remaining views with remote-select fields
• Signals to users that these are remote-search fields rather than static dropdowns, and names what's being searched

How did you approach the change?

• Changed "Search by title" → "Type to search workshops…" on the workshop fields in:
  • stories/_form.html.erb
  • workshop_logs/_form.html.erb
  • workshop_variations/_form.html.erb
  • workshop_variation_ideas/_form.html.erb
• Changed "Search by name" → "Type to search organizations…" on the organization fields in:
  • stories/_form.html.erb
  • people/_affiliation_fields.html.erb

UI Testing Checklist

• On a new Story form, confirm the workshop field placeholder reads "Type to search workshops…"
• On the same Story form, confirm the organization field placeholder reads "Type to search organizations…"
• On a new WorkshopLog form, confirm the workshop field placeholder reads "Type to search workshops…"
• On a new WorkshopVariation form (admin), confirm the workshop field placeholder reads "Type to search workshops…"
• On a new WorkshopVariationIdea form (admin), confirm the workshop field placeholder reads "Type to search workshops…"
• On a Person's affiliation fields, confirm the organization field placeholder reads "Type to search organizations…"
• Confirm typing in each field still surfaces results and selection still saves

Anything else to add?

• Follow-up to Clarify workshop search prompt on StoryIdea form #1509, which scoped its text change to StoryIdea only

[jmilljr24]

Thanks!