Clarify My Ships ESI prompts as scope grants, not Auth re-registration

[TrueMessenger]

Summary

• The blocked-characters warning on My Ships now explains that Fit Check needs an extra ESI grant to read the listed characters' ship hangars, and that this is separate from the character's Auth registration (which is unaffected) - the previous "These characters need ESI access" + "Connect ESI access" wording read as if the character had to be re-registered with Auth.
• The warning's button is now "Grant access for N character(s)" (pluralized via blocktranslate count).
• The info banner's button and the filter-bar shortcut now say "Grant" instead of "Connect".

Test plan

• manage.py test fitcheck - 833 tests pass
• manage.py check clean; makemigrations fitcheck --check --dry-run - no changes
• Text-only template change; the visibility conditions and grant URL are untouched (existing TestConnectEsiVisibility assertions pin both).