feat(scripts): read-only, allow-listed Files global for site scripts; Delmia test receiver parses recipe files

Script file access (design docs/plans/2026-09-28-script-file-access-design.md): Files.ReadTextAsync /
ReadLinesAsync / ExistsAsync on site ScriptGlobals (+ Instance.Files), backed by the site-singleton
ScriptFileReader. The one host-mediated exception to the System.IO ban - scripts still never name a
System.IO type. OFF by default: ScadaBridge:SiteRuntime:ScriptFileAccess:AllowedRoots (empty = every call
throws Disabled) + MaxFileBytes (1 MiB, validated 1..64 MiB, roots must be absolute). Guard: fully
qualified, no device paths / ADS, canonical path strictly inside a root (directory-boundary match), no
reparse point on the file or any directory below the root, size cap before and during the read.
Errors are one Commons type, ScriptFileAccessException(+ScriptFileAccessFailure); Commons.Types.Scripts
joins the default script imports on every surface so it binds by short name. Mirrored on
ScriptCompileSurface (CompileFiles, parity-pinned) and the Test Run sandbox (binds, refuses Disabled).
Inbound (central) scripts do not get it.

Rig: docker/recipes (sample RecipeValueName,RecipeValue files incl. an invalid one) bind-mounted
read-only at /app/recipes on both site-a nodes with AllowedRoots [/app/recipes]. The TestMesMachine
SimDelmiaRecipe simulator now reads + parses the downloaded file, converts each value to its recipe tag's
type and loads it all-or-nothing (14 new TestDelmiaReceiver attributes); verify-mes-test-machine.sh
group A covers accept / re-download / invalid lines / NotFound / OutsideAllowedRoots, VERIFY_GROUPS
selects groups (rig: AD).

docker/docker-compose.yml

@@ -238,6 +238,7 @@ services:
       - "9023:8083"   # gRPC streaming
     volumes:
       - ./site-a-node-a/appsettings.Site.json:/app/appsettings.Site.json:ro
+      - ./recipes:/app/recipes:ro   # script file access (Files global) — sample Delmia recipes
       - site-a-node-a-data:/app/data
       # Same named volume, mounted a second time OUTSIDE the content root (/app).
       # Secrets 0.6.2 refuses a store path under the content root; this mount is
@@ -274,6 +275,7 @@ services:
       - "9024:8083"   # gRPC streaming
     volumes:
       - ./site-a-node-b/appsettings.Site.json:/app/appsettings.Site.json:ro
+      - ./recipes:/app/recipes:ro   # script file access (Files global) — sample Delmia recipes
       - site-a-node-b-data:/app/data
       # Same named volume, mounted a second time OUTSIDE the content root (/app).
       # Secrets 0.6.2 refuses a store path under the content root; this mount is