fix(ecstore): resolve Windows drive paths in URL endpoints (#8629)

On Windows, URL endpoints such as http://host:9000/C:/data{1...4} (the only
form multi-node and pool-expansion layouts accept) produced the disk path
`/C:/data1`: `try_from` stripped the synthetic slash, but `Url::set_path`
put it back, and `get_file_path` only removed it for `file` endpoints.
Windows resolves `/C:/data1` as an invalid `C:` component under the current
drive, so disk validation and `resolve_local_disk_root` failed.

- `get_file_path` now restores `/X:/...` to `X:/...` for every scheme on
  Windows; URL paths without a drive (`/export1`, `/C:foo`) are unchanged.
- UNC shares (`\\nas\share\d1`, `//nas/share/d1`, `\\?\UNC\...`) are rejected
  with an explicit error instead of becoming a file URL whose host is the
  share server and whose path drops the share name.
- A drive root (`http://host:9000/D:/`) is accepted in URL form, matching
  the path-style `D:\` endpoint that was already accepted.
- The "distinct physical disks" error explains on Windows that directories
  on one volume share a device identity, alongside the existing
  RUSTFS_UNSAFE_BYPASS_DISK_CHECK hint.
- The Windows filesystem lane now runs on layout changes and runs the
  layout::endpoint:: tests; new Windows tests carry the windows_ prefix.
- Document Windows endpoint forms, the same-volume check, and the SNSD
  expansion limit in cluster-lifecycle-operations.md.

.github/workflows/windows-filesystem.yml

@@ -19,6 +19,7 @@ on:
     branches: [ main ]
     paths:
       - "crates/ecstore/src/disk/**"
+      - "crates/ecstore/src/layout/**"
       - "crates/ecstore/src/store/init_format.rs"
       - "crates/ecstore/src/bucket/utils.rs"
       - "crates/ecstore/Cargo.toml"
@@ -36,6 +37,7 @@ on:
     branches: [ main ]
     paths:
       - "crates/ecstore/src/disk/**"
+      - "crates/ecstore/src/layout/**"
       - "crates/ecstore/src/store/init_format.rs"
       - "crates/ecstore/src/bucket/utils.rs"
       - "crates/ecstore/Cargo.toml"
@@ -99,6 +101,10 @@ jobs:
         shell: pwsh
         run: cargo test -p rustfs-ecstore --lib windows_ -- --nocapture
 
+      - name: Test endpoint path parsing
+        shell: pwsh
+        run: "cargo test -p rustfs-ecstore --lib layout::endpoint:: -- --nocapture"
+
       - name: Test startup temporary-directory cleanup
         shell: pwsh
         run: cargo test -p rustfs-ecstore --lib cleanup_tmp_on_startup_ -- --nocapture