fix(correctness): close Theme 10 — 5 data-integrity / serialisation findings

Final themed batch. 5 well-localised correctness fixes.

Serialisation precision:
- ESG-020: DatabaseGateway.JsonElementToParameterValue probes
  TryGetInt64 → TryGetDecimal → GetDouble, so a script's high-precision
  decimal SQL parameter survives the cached-write retry round-trip
  without silent precision loss. 3 new regression tests.

Template engine correctness:
- TE-018: DiffService gains ComputeConnectionsDiff over
  FlattenedConfiguration.Connections, mirroring the existing entity-diff
  shape and pairing with the Theme 1 TE-017 hash-coverage fix. A
  ConfigurationDiff record extension in Commons is flagged as a follow-up.
- TE-019: TemplateResolver.BuildInheritanceChain now walks via the
  int? ParentTemplateId directly — only null means "no parent". A real
  Id of 0 (the prior special-cased sentinel) now walks the chain like
  any other node, matching the TemplateEngine-013 CycleDetector fix.
  Regression of TE-013 closed.
- TE-020: All 5 Create* paths in TemplateService + SharedScriptService
  re-ordered to save-first → log-with-real-Id → save-audit (matching
  the InstanceService pattern). Create* audit rows no longer carry a
  literal "0" EntityId.

Doc deferral:
- Transport-012: Component-Transport.md §Audit Trail now spells out that
  the BundleImportId repository filter IS wired (in CentralUiRepository),
  but the Audit-Log-Viewer UI dropdown + summary-row hyperlink are a
  deferred CentralUI follow-up. CLI workaround documented
  (audit query --bundle-import-id).

11+ new regression tests (3 ESG, 4 DiffService, 3 TemplateResolver, 4
TemplateService, 1 SharedScriptService). Build clean; ESG 72/72,
TemplateEngine 324/324. README regenerated: 1 pending of 481 total.

Session-to-date: 135 of 136 originally-open Theme findings closed
across 10 themes in 10 commits.

code-reviews/Transport/findings.md

@@ -499,7 +499,7 @@ bundle prompt is surfaced AFTER the manifest+hash check, and that a dedicated
 |--|--|
 | Severity | Low |
 | Category | Documentation & comments |
-| Status | Open |
+| Status | Resolved |
 | Location | `docs/requirements/Component-Transport.md` §Audit Trail, `src/ScadaLink.ConfigurationDatabase/Repositories/CentralUiRepository.cs:148` |
 
 **Description**
@@ -518,6 +518,12 @@ it's reasonable to flag.
 Either implement the filter dropdown + summary-row link in the Configuration
 Audit Log Viewer, or note the deferral in the design doc.
 
-**Resolution**
+**Resolution (2026-05-28):**
 
-_Unresolved._
+Took the "note the deferral in the design doc" path. `docs/requirements/Component-Transport.md`
+§Audit Trail's "Correlation:" paragraph now spells out that the repository filter on
+`BundleImportId` IS wired (in `CentralUiRepository.QueryConfigurationAuditAsync`)
+but the Audit-Log-Viewer UI surface — the dropdown + `BundleImported` hyperlink —
+is a deferred UI follow-up. Operators have a workaround via the existing
+`audit query --bundle-import-id` CLI flag. The UI work belongs in the CentralUI
+backlog; implementing it here would expand scope beyond a doc fix.