Fix spelling and typos across codebase

[Copilot]

Corrects spelling errors in code, comments, and documentation that impact code readability and searchability.

Changes

FPC.js

• R2_CAHE_LOGGEDIN_USERS → R2_CACHE_LOGGEDIN_USERS (variable name)
• semultaniosly → simultaneously (comment)
• recieved → received (comment)
• sens → sense (comment)

package.json

• nodejent → node (keyword)

README.md

• untill → until
• updayed → updated
• everething → everything

The variable name change improves code searchability and prevents potential confusion when referencing the logged-in user cache configuration.

Original prompt

Add improvements

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