fix(docs): correct the architecture page against server 0.9.0

[justinmclean]

Corrects the architecture page and its shard diagram.

• TLS-wrapped TCP and WSS connections are handed to other shards as raw sockets before the handshake, like plaintext TCP. Only QUIC and HTTP stay on shard 0. The round-robin includes shard 0 by default.
• A partition request goes into the owning shard's channel.
• cores= in the NUMA mode is one count applied to every listed node.
• Tokio's 512 is the maximum of a blocking pool that grows on demand.
• 4096 is the io_uring submission queue size.
• Storage: state/log is an empty file, a fresh partition has only superblock.a, journal.wal is checkpointed into snapshot.bin, and current_config.toml is rewritten at boot with the bound addresses and without secrets.
• A sealed segment can exceed the segment size by up to one batch.
• Removes "inspired by the Seastar framework", which the repo does not state.

Verified against the server-0.9.0 tag: core/server/src/boot/listeners.rs, core/shard/src/coordinator.rs, core/shard/src/router.rs, core/cpu_allocation/src/lib.rs, core/server_common/src/executor.rs, core/server_common/src/bootstrap.rs, core/server/src/config_writer.rs, core/journal/src/superblock.rs, core/metadata/src/impls/metadata.rs, core/parVerified against the server-0.9.0tag:core/server/soml. The storage layout was also checked on a running apache/iggy:0.9.0` container.