Clarify monitor target modes + dashboard link on create

[developersdigest]

Follow-up UX polish on firecrawl monitor (the search-target support shipped in #142).

monitor create --help — clearer target modes

Adds a Target modes section so it's obvious which flag does what:

--page <url>                    Watch a single page for changes
--scrape-urls <url,url,...>     Watch a batch of pages for changes
--crawl-url <root-url>          Watch a whole site — crawls and diffs every page each check
--queries <query,...> + --goal  Watch the web via search — alerts on NEW results matching --goal

Dashboard link on create

After a successful create, prints the Cloud dashboard link + a run-now hint to stderr — interactive only (process.stdout.isTTY), so pipes and --output stay clean for scripting:

  Monitor created · 019f05af-9bf6-...
  Open in dashboard:  https://www.firecrawl.dev/app/monitoring/019f05af-9bf6-...
  Trigger a check:    firecrawl monitor run 019f05af-9bf6-...

(Skipped for self-hosted APIs, which have no web dashboard.)

Skill clarity

firecrawl-monitor SKILL.md gains a target-mode table so agents pick the right flags up front (single page / URL batch / whole-site crawl / web search).

Version → 1.19.21. tsc clean, 4/4 monitor tests pass.