docs: README — reinstate verified v2 links + flag v1 archive

Two follow-ups from the post-PR-7.2 audit:

1. Reinstate verified-current architecture deep-dive links that the
   doc-cleanup pass dropped pending verification:
   - docs/OpcUaServer.md (server composition, namespace fan-out,
     Polly invoker)
   - docs/IncrementalSync.md (driver-backend rediscovery + config
     publishes)
   - docs/ReadWriteOperations.md (driver vs virtual vs scripted-alarm
     dispatch)
   All three reference live Phase 6.2 / Phase 7 features and the
   current GenericDriverNodeManager / CapabilityInvoker / OTOPCUA0001
   analyzer codepaths.

2. Restructured the README link table into three logical sections —
   "Architecture deep-dives" / "Drivers" / "Clients" — and added a
   "v1 archive" section pointing at docs/v1/ for the retired in-process
   MXAccess docs.

3. Removed the dead docs/Configuration.md link (the file moved to
   docs/v1/Configuration.md in the v1 archive sweep). All 16 link
   targets in the new README now resolve.

Plus: physically removed the 9 leftover Driver.Galaxy.* directories
from src/ and tests/ that PR 7.2's git rm cleared from tracking but
left as orphan bin/obj scaffolding on disk. No tracked-content
change for that part.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -72,6 +72,21 @@ See [docs/Client.CLI.md](docs/Client.CLI.md) and [docs/Client.UI.md](docs/Client
 
 ## Documentation
 
+### Architecture deep-dives
+
+| Topic | Doc |
+|---|---|
+| OPC UA server composition, namespace fan-out, Polly invoker | [docs/OpcUaServer.md](docs/OpcUaServer.md) |
+| Address space layout | [docs/AddressSpace.md](docs/AddressSpace.md) |
+| Read / Write dispatch (driver vs virtual vs scripted-alarm) | [docs/ReadWriteOperations.md](docs/ReadWriteOperations.md) |
+| Incremental sync (driver-backend rediscovery + config publishes) | [docs/IncrementalSync.md](docs/IncrementalSync.md) |
+| Service hosting (Server + Admin + optional historian sidecar) | [docs/ServiceHosting.md](docs/ServiceHosting.md) |
+| Security (transport, LDAP, certificates) | [docs/security.md](docs/security.md) |
+| Redundancy | [docs/Redundancy.md](docs/Redundancy.md) |
+| Status dashboard | [docs/StatusDashboard.md](docs/StatusDashboard.md) |
+
+### Drivers
+
 | Topic | Doc |
 |---|---|
 | Driver specs (per-driver capability surface, config, addressing) | [docs/v2/driver-specs.md](docs/v2/driver-specs.md) |
@@ -79,12 +94,22 @@ See [docs/Client.CLI.md](docs/Client.CLI.md) and [docs/Client.UI.md](docs/Client
 | Modbus / S7 / AbCip / AbLegacy / TwinCAT / FOCAS / OpcUaClient | [docs/drivers/](docs/drivers/) |
 | Galaxy parity rig (mxaccessgw setup) | [docs/v2/Galaxy.ParityRig.md](docs/v2/Galaxy.ParityRig.md) |
 | Galaxy performance + tracing | [docs/v2/Galaxy.Performance.md](docs/v2/Galaxy.Performance.md) |
-| Service hosting | [docs/ServiceHosting.md](docs/ServiceHosting.md) |
-| Security (transport, LDAP, certificates) | [docs/security.md](docs/security.md) |
-| Redundancy | [docs/Redundancy.md](docs/Redundancy.md) |
-| Address space | [docs/AddressSpace.md](docs/AddressSpace.md) |
-| Configuration | [docs/Configuration.md](docs/Configuration.md) |
-| Status dashboard | [docs/StatusDashboard.md](docs/StatusDashboard.md) |
+
+### Clients
+
+| Topic | Doc |
+|---|---|
+| Client CLI | [docs/Client.CLI.md](docs/Client.CLI.md) |
+| Client UI (Avalonia desktop) | [docs/Client.UI.md](docs/Client.UI.md) |
+
+### v1 archive
+
+The original v1 in-process MXAccess docs (Galaxy.Host topology,
+Configuration env vars, AlarmTracking, DataTypeMapping,
+HistoricalDataAccess, Subscriptions, etc.) are preserved under
+[docs/v1/](docs/v1/) — historical reference only. PR 7.2 retired the
+v1 architecture on 2026-04-30; current state is documented in the
+sections above.
 
 ## License