Add SVN operation acceptance coverage

[lzl51230]

Scope

Extend the real same-session SVN watcher integration fixture introduced for #1113. Current coverage proves a tracked edit and unversioned addition, but does not execute the user-facing SVN operation workflows.

Acceptance cases

• Clean svn update that changes/adds/removes source files.
• Commit after already-synchronized content, including the expected pipeline no-op.
• Delete and rename removing stale graph state.
• Conflict contents as pipeline input.
• Busy/failure retry with the prior graph queryable.
• Existing full-route fallback through the same pre-warmed MCP server.

Run these through one real watcher/server lifecycle on Linux, macOS, and Windows.

[DeusData]

Tracked as 0.9.2-rc acceptance coverage for #1113/#1127. These are user-facing workflows, so successful merge should not rely only on synthetic status snapshots. Keep the fixture local and deterministic, and ensure failure/busy cases prove the prior graph remains queryable rather than merely checking callback counts.