[PB-2394] feat: calculate yesterday usage and first usage on first /usage call

[apsantiso]

⚠️ Important: This PR implements the calculation logic but does NOT change the response returned to users. The /usage endpoint continues to return the existing implementation.

Implements incremental usage calculation logic to track user storage usage over time. This PR adds the calculation and delta storage functionality without changing the current user-facing response, allowing us to monitor the new system's behavior before switching over.

How a request to/usage works

1. Find last usage record: Query the latest usage record by period field (last_usage)
2. Handle first-time users: If no usage record exists, calculate delta from user creation date to yesterday and create initial usage record, then skip to step 4
3. Handle existing users: If last_usage exists, check if last_usage.period === currentDate - 1 day:

• Yes: Proceed to step 4
• No: Calculate delta from last_usage.period to currentDate - 1 day, save this delta in usage table with yesterday's date

4. Calculate historical usage: Sum all deltas from usage table (PENDING)
5. Calculate today's usage: Sum current day delta directly from files table (PENDING)
6. Return total: Sum both results and return to user (PENDING)

How replacing a file works

1. File update: The file is replaced successfully
2. Did file size changed?: We calculate delta by comparing the old file size and the new file size
3. Save delta if needed: If there's a change, we store delta with daily type

Why are files created and updated on the same day ignored?

These files will be included in the next delta calculation (the following day). If we also save a delta for them on the current day, it would result in double-counting and incorrect calculations.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
89.2% Coverage on New Code
0.0% Duplication on New Code

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