feat(database): introduce Snowflake IDs generator

[Altahrim]

Summary

• Introduce Snowflake IDs generator/decoder
  See https://en.wikipedia.org/wiki/Snowflake_ID for more info

• Documentation in feat: add Snowflake IDs information documentation#13811

TODO

• Wait for tests in feat(previews): Use SnowflakeId generator for previews #55710 to turn green before merging

Implementation notes

Format

Snowflake IDs use 64 bits. I chose to split them like this:

• 1 bit : unused, PHP use signed integers
• 31 bits: Timestamp from 2025-10-01. Allows to store a bit more than 68 years.
• 10 bits: Milliseconds
• 9 bits: Server ID
• 1 bit : CLI or Web (see "Sequence ID" later)
• 12 bits: Sequence ID

Issues with 32 bits

On 32 bits systems, 64 bits int are stored in float.
The problem is float are losing precision with large numbers like numbers used here so when loading a number, the sequence ID can change.
So, Snowflake IDs are given as string for 64 bits and 32 bits systems.

Server ID

For now, take a hash of hostname. Can be improved with a mapping of server with a server ID.

Sequence ID

PHP-FPM and Apache module share memory and allow the use of apcu_inc to keep sequence ID.
For CLI, fallback to random (shared cache dropped)

Decode tool

occ decode-snowflake 6768789079123765868
+--------------------+-------------------------+
| Snowflake ID       | 6768789079123765868     |
| Seconds            | 1575981518              |
| Milliseconds       | 50                      |
| Created from CLI   | no                      |
| Server ID          | 441                     |
| Sequence ID        | 2668                    |
| Creation timestamp | 3335258318.050          |
| Creation date      | 2075-09-09 12:38:38.050 |
+--------------------+-------------------------+

TODO

• Add test for 32 bit generation

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (see feat: add Snowflake IDs information documentation#13811)
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

[SystemKeeper]

Is it additional to #55710? 🤔

[Altahrim]

Is it additional to #55710? 🤔

Not really… We discussed it at Contributor Week but I lacked time to finish so I just pushed what I had.
Implementations are a bit different… I added a bit to know if ID was created from CLI because we can't use APCu for it.

[Altahrim]

Unrelated red CI, documentation added in nextcloud/documentation#13811