fix(transport): blocker heuristic no longer hard-blocks valid imports — local declarations excluded, denylist extended, template-script findings downgraded to warnings

#05-T19. Import name-resolution findings are now split by origin: template-script
(and attribute-default-expression) references become non-blocking advisory
warnings (ConflictKind.Warning + ImportResult.Warnings) since the design-time
deploy gate re-validates authoritatively; ApiMethod-script references stay hard
errors (SemanticValidationException / ConflictKind.Blocker) as they have no
downstream gate. Names declared locally in a body (Roslyn-parsed local functions
/ methods) are excluded so a script's own helper isn't flagged; KnownNonReferenceNames
extended with common BCL/LINQ/SQL surface. DetectBlockersAsync and
RunSemanticValidationAsync Pass 1 apply the identical split so preview and apply
agree. Rollback/hard-fail tests retargeted to ApiMethods (the still-hard-failing
vehicle). CentralUI preview renders the new Warning badge/advisory.

Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj

docs/requirements/Component-Transport.md

@@ -25,7 +25,7 @@ As of M8 (T18), Transport is no longer limited to central-only configuration: it
 - Encrypt content with AES-256-GCM + PBKDF2-SHA256 (600 000 iterations) when a passphrase is supplied; leave content plaintext with a UI warning and an `UnencryptedBundleExport` audit event when none is given.
 - Validate `manifest.json` on upload: format version gating, SHA-256 content hash verification.
 - Manage in-memory `BundleSession` objects: 30-minute TTL, 3-strike passphrase lockout per session.
-- Compute a per-artifact diff between bundle contents and the target environment, classifying each artifact as Identical, Modified, New, or a Blocker.
+- Compute a per-artifact diff between bundle contents and the target environment, classifying each artifact as Identical, Modified, New, a Blocker (import-stopping), or a Warning (advisory, non-blocking).
 - Apply user-supplied conflict resolutions (Add, Overwrite, Skip, Rename) in a single EF transaction, running two-tier semantic validation before committing: a minimal name-resolution scan over the merged target (fails fast on unresolved SharedScript / ExternalSystem identifiers), then the full `SemanticValidator` from `ZB.MOM.WW.ScadaBridge.TemplateEngine` over each imported template's per-template `FlattenedConfiguration`.
 - Emit `BundleExported`, `BundleImported`, `BundleImportFailed`, `UnencryptedBundleExport`, `BundleImportUnlockFailed`, `BundleImportAlarmScriptUnresolved`, `BundleImportCompositionUnresolved`, and `BundleImportBaseTemplateUnresolved` audit events via `IAuditService`.
 - Thread a `BundleImportId` correlation GUID through every per-entity `AuditLogEntry` written during `ApplyAsync` via a scoped `IAuditCorrelationContext`.
@@ -227,7 +227,9 @@ Bulk "Apply to all" at the top (Overwrite / Skip / Rename), overridable per row.
 
 Bundle references that cannot be satisfied in either the bundle or the target DB (e.g., a template references a shared script that is neither in the bundle nor pre-existing) appear as **blocker rows** — Apply is disabled until they are resolved (typically by skipping the dependent artifact or re-exporting with dependencies). Unmapped/unmatched sites and connections that the operator did not set to Create-new also surface as blocker rows here, mirroring the Step-3 Map decisions.
 
-**Blocker-scan heuristic boundaries.** The scanner walks `TemplateScript.Code`, `TemplateAttribute.Value`, and `ApiMethod.Script` looking for top-level `Identifier(` or `Identifier.` tokens. To keep the heuristic usable on real script bodies it (a) skips identifiers preceded by `.` (member access — `obj.Method()` does not flag `Method`); (b) does NOT scan `TemplateAttribute.DataSourceReference` (an OPC UA address path, never script source); and (c) filters out a small `KnownNonReferenceNames` denylist of .NET stdlib types (`Convert`, `DateTimeOffset`, `ToString`, `Dispose`, `UtcNow`, …), ScadaBridge runtime API roots (`Notify`, `Database`, `ExternalSystem`, `Scripts`, `Instance`, `Parameters`, `Attributes`, `Route`, …), and common SQL keywords that appear inside string literals (`COUNT`, `SELECT`, `FROM`, …). Both the diff-step `DetectBlockersAsync` and the Apply-time `RunSemanticValidationAsync` Pass 1 share this filter, so the diff preview and the Apply gate agree.
+**Blocker-scan heuristic boundaries.** The scanner walks `TemplateScript.Code`, `TemplateAttribute.Value`, and `ApiMethod.Script` looking for top-level `Identifier(` or `Identifier.` tokens. To keep the heuristic usable on real script bodies it (a) skips identifiers preceded by `.` (member access — `obj.Method()` does not flag `Method`); (b) does NOT scan `TemplateAttribute.DataSourceReference` (an OPC UA address path, never script source); (c) excludes names **declared locally in the body** — every `LocalFunctionStatement` / `MethodDeclaration` identifier is collected via a Roslyn script-kind parse, so a script's own helper (`decimal ComputeRate(...) => …; return ComputeRate(x);`) is not mistaken for a missing SharedScript; and (d) filters out a `KnownNonReferenceNames` denylist of .NET stdlib types (`Convert`, `DateTimeOffset`, `Regex`, `StringBuilder`, `Parse`, LINQ operators, …), ScadaBridge runtime API roots (`Notify`, `Database`, `ExternalSystem`, `Scripts`, `Instance`, `Parameters`, `Attributes`, `Route`, …), and common SQL keywords that appear inside string literals (`COUNT`, `SELECT`, `FROM`, `HAVING`, `VALUES`, …). Both the diff-step `DetectBlockersAsync` and the Apply-time `RunSemanticValidationAsync` Pass 1 share this filter, so the diff preview and the Apply gate agree.
+
+**Severity split — template-script findings are advisory, ApiMethod findings block.** A residual unresolved identifier (one the heuristic could not filter) is classified by its **origin**. Findings from **template scripts** and **attribute default expressions** are non-blocking **warnings**: they surface as `ConflictKind.Warning` rows in the preview and ride on `ImportResult.Warnings` after a successful apply — the import proceeds because the authoritative design-time **deploy gate re-validates** the script with a real compile (`ScriptCompiler.TryCompile`), so a heuristic false positive here must never stop a valid import. Findings from **ApiMethod scripts** remain **hard errors** (`ConflictKind.Blocker` in preview; `SemanticValidationException` at apply) because inbound API methods have no downstream design-time gate — the import review is their only pre-runtime check. The split is applied identically in `DetectBlockersAsync` and `RunSemanticValidationAsync` Pass 1 so preview and apply agree.
 
 **Step 5 — Confirm.** Final summary plus a "N instances will become stale" warning enumerating affected instances (a real count as of M8 — see "Stale-Instance Signaling"). User types the source environment name to confirm (typo-resistant gate at the prod boundary).
 
@@ -307,7 +309,8 @@ As of M8 the import result enumerates affected instances for real (closing the p
 | Unlock | Wrong passphrase | Step 2 error; 3rd wrong attempt invalidates session, audit `BundleImportUnlockFailed` |
 | Map | Source site/connection neither auto-matched nor mapped/created | Listed as a blocker row in the Map step (UI) / Diff step; cannot Apply until mapped or set to Create-new. CLI aborts before apply unless `--create-missing-sites` / `--create-missing-connections` is given |
 | Map | `CreateNew` selected but the bundle does not carry that site/connection's config | Blocker — Create-new requires the full config to be present in the bundle payload |
-| Preview | Bundle references shared script not in bundle and not in target DB | Listed as a blocker row in the Diff step; cannot Apply until resolved |
+| Preview | ApiMethod script references shared script / external system not in bundle and not in target DB | Listed as a **blocker** row in the Diff step; cannot Apply until resolved (no downstream deploy gate for ApiMethods) |
+| Preview | Template script references shared script / external system not in bundle and not in target DB | Listed as an advisory **warning** row; import proceeds — the design-time deploy gate re-validates the script authoritatively |
 | Apply | Semantic validation fails (call target type mismatch, etc.) | Modal: "Validation failed — N errors", per-error list, no DB writes |
 | Apply | DB transaction fails | Rollback; full transactional guarantee — nothing partial lands; `BundleImportFailed` audit row written outside the rolled-back transaction |
 | Session | TTL expired | Diff step onward, refresh prompts re-upload |