refactor: flatten Microsoft skills from nested to flat directory structure

Rewrote sync_microsoft_skills.py (v4) to use each SKILL.md's frontmatter
'name' field as the flat directory name under skills/, replacing the nested
skills/official/microsoft/<lang>/<category>/<service>/ hierarchy.

This fixes CI failures caused by the indexing, validation, and catalog
scripts expecting skills/<id>/SKILL.md (depth 1).

Changes:
- Rewrite scripts/sync_microsoft_skills.py for flat output with collision detection
- Update scripts/tests/inspect_microsoft_repo.py for flat name mapping
- Update scripts/tests/test_comprehensive_coverage.py for name uniqueness checks
- Delete skills/official/ nested directory
- Add 129 Microsoft skills as flat directories (e.g. skills/azure-mgmt-botservice-dotnet/)
- Move attribution files to docs/ (LICENSE-MICROSOFT, microsoft-skills-attribution.json)
- Rebuild skills_index.json, CATALOG.md, README.md (845 total skills)

skills/azure-eventhub-rust/SKILL.md

@@ -0,0 +1,127 @@
+---
+name: azure-eventhub-rust
+description: |
+  Azure Event Hubs SDK for Rust. Use for sending and receiving events, streaming data ingestion.
+  Triggers: "event hubs rust", "ProducerClient rust", "ConsumerClient rust", "send event rust", "streaming rust".
+package: azure_messaging_eventhubs
+---
+
+# Azure Event Hubs SDK for Rust
+
+Client library for Azure Event Hubs — big data streaming platform and event ingestion service.
+
+## Installation
+
+```sh
+cargo add azure_messaging_eventhubs azure_identity
+```
+
+## Environment Variables
+
+```bash
+EVENTHUBS_HOST=<namespace>.servicebus.windows.net
+EVENTHUB_NAME=<eventhub-name>
+```
+
+## Key Concepts
+
+- **Namespace** — container for Event Hubs
+- **Event Hub** — stream of events partitioned for parallel processing
+- **Partition** — ordered sequence of events
+- **Producer** — sends events to Event Hub
+- **Consumer** — receives events from partitions
+
+## Producer Client
+
+### Create Producer
+
+```rust
+use azure_identity::DeveloperToolsCredential;
+use azure_messaging_eventhubs::ProducerClient;
+
+let credential = DeveloperToolsCredential::new(None)?;
+let producer = ProducerClient::builder()
+    .open("<namespace>.servicebus.windows.net", "eventhub-name", credential.clone())
+    .await?;
+```
+
+### Send Single Event
+
+```rust
+producer.send_event(vec![1, 2, 3, 4], None).await?;
+```
+
+### Send Batch
+
+```rust
+let batch = producer.create_batch(None).await?;
+batch.try_add_event_data(b"event 1".to_vec(), None)?;
+batch.try_add_event_data(b"event 2".to_vec(), None)?;
+
+producer.send_batch(batch, None).await?;
+```
+
+## Consumer Client
+
+### Create Consumer
+
+```rust
+use azure_messaging_eventhubs::ConsumerClient;
+
+let credential = DeveloperToolsCredential::new(None)?;
+let consumer = ConsumerClient::builder()
+    .open("<namespace>.servicebus.windows.net", "eventhub-name", credential.clone())
+    .await?;
+```
+
+### Receive Events
+
+```rust
+// Open receiver for specific partition
+let receiver = consumer.open_partition_receiver("0", None).await?;
+
+// Receive events
+let events = receiver.receive_events(100, None).await?;
+for event in events {
+    println!("Event data: {:?}", event.body());
+}
+```
+
+### Get Event Hub Properties
+
+```rust
+let properties = consumer.get_eventhub_properties(None).await?;
+println!("Partitions: {:?}", properties.partition_ids);
+```
+
+### Get Partition Properties
+
+```rust
+let partition_props = consumer.get_partition_properties("0", None).await?;
+println!("Last sequence number: {}", partition_props.last_enqueued_sequence_number);
+```
+
+## Best Practices
+
+1. **Reuse clients** — create once, send many events
+2. **Use batches** — more efficient than individual sends
+3. **Check batch capacity** — `try_add_event_data` returns false when full
+4. **Process partitions in parallel** — each partition can be consumed independently
+5. **Use consumer groups** — isolate different consuming applications
+6. **Handle checkpointing** — use `azure_messaging_eventhubs_checkpointstore_blob` for distributed consumers
+
+## Checkpoint Store (Optional)
+
+For distributed consumers with checkpointing:
+
+```sh
+cargo add azure_messaging_eventhubs_checkpointstore_blob
+```
+
+## Reference Links
+
+| Resource | Link |
+|----------|------|
+| API Reference | https://docs.rs/azure_messaging_eventhubs |
+| Source Code | https://github.com/Azure/azure-sdk-for-rust/tree/main/sdk/eventhubs/azure_messaging_eventhubs |
+| crates.io | https://crates.io/crates/azure_messaging_eventhubs |