Move captive_portal inside wifi/

[anarchyysm]

Problem

Goal: captive_portal stops being a root folder and lives under wifi/captive_portal/.
Estimated effort: 0.5 day

Proposed Solution

• Move code from Applications/captive_portal/ into Applications/wifi/captive_portal/ (or update all references accordingly)
• Update all captive portal paths to use TOS_PATH_CAPTIVE and TOS_PATH_CAPTIVE_TMPL
• Remove old STORAGE_DIR_CAPTIVE after migration
• Update screens/wifi/ to reference the new captive portal paths
• Test: capture a password via captive portal — confirm passwords.json lands in wifi/captive_portal/

Use Case

No response

Alternatives Considered

No response