docs: Adds ADR on the migration to UUID7

docs/src/architecture/09_architecture_decisions/0009-uuid7-vs-ulid.md

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+---
+    title: 0009 UUIDv7 vs ULID
+    adr:
+        author: Assistant
+        created: 17-Oct-2024
+        status: proposed
+    tags:
+        - uuid
+        - identifiers
+---
+
+## Context
+
+The system needs globally unique identifiers for various entities and resources.
+Currently, we use ULIDs (Universally Unique Lexicographically Sortable Identifiers) in some parts of the system.
+With the recent standardization of UUIDv7 through [RFC 9562], we need to evaluate our identifier strategy.
+
+## Assumptions
+
+* We need time-ordered, globally unique identifiers for certain system components
+* We need non-time-ordered unique identifiers for type identification
+* Our systems must interact with various external systems and databases
+
+## Decision
+
+We will:
+
+* Use UUIDv7 for all time-bound unique identifiers (replacing ULID usage)
+* Use UUIDv4 for type-specific identifiers where time ordering is not required
+* Phase out ULID usage in favor of UUIDv7
+
+### Rationale
+
+* UUIDv7 provides similar benefits to ULID:
+  * Time-ordered
+  * Globally unique
+  * Contains timestamp information
+* UUIDv7 has several advantages over ULID:
+  * Standardized through RFC 9562
+  * Wider system compatibility (native UUID support)
+  * No special encoding requirements
+  * Clear disambiguation from UUIDv4 (allowing two distinct identifier spaces)
+  * Eliminates need for custom ULID code
+  * Better database indexing support
+* Standard UUID implementations are widely available across programming languages and platforms
+
+### Implementation Guidelines
+
+* New features should exclusively use:
+  * UUIDv7 for time-ordered identifiers
+  * UUIDv4 for non-time-ordered type identifiers
+* Existing ULID implementations should be migrated to UUIDv7 during regular maintenance cycles
+* Database schemas should use UUID types rather than string/custom types
+* API contracts should specify UUID format requirements in their documentation
+
+## Risks
+
+* Migration from existing ULID implementations requires careful planning
+* Some existing data may need conversion
+* Team members need to understand when to use UUIDv4 vs UUIDv7
+
+## Consequences
+
+### Positive
+
+* Improved system interoperability
+* Reduced custom code maintenance
+* Better alignment with industry standards
+* Simplified database operations
+* Two distinct identifier spaces (v4 and v7) for different use cases
+
+### Negative
+
+* Migration effort required for existing ULID implementations
+* Team training needed for proper UUID version selection
+
+## More Information
+
+* [RFC 9562 - UUIDv7 Specification](https://datatracker.ietf.org/doc/rfc9562/)
+* [ULID Specification](https://github.com/ulid/spec)
+
+[RFC 9562]: https://datatracker.ietf.org/doc/rfc9562/