feat(lang): L9 resource files - registry ... from

registry NAME of RECORD [as PREFIX] from "file.lres" fills a registry from a data
file of key { field: value } entries, read at compile time with the record as its
schema: every entry is checked like a def, errors name the resource file's line,
nested records and lists of them are bare { } / [{ }] typed by their fields, and
values are expressions in the registry's module. The entries are compiled in, so
nothing parses at start-up and a build that succeeds has validated its resources.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/lang/data/tools.lres

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+# tools.lres - the tools a camp keeps, read by resources.ludic's registry when it is compiled
+axe {
+  name: "Axe"
+  weight: 1.5
+  uses: [{ verb: "Chop", minutes: 20 }, { verb: "Split", minutes: 10 }]
+}
+lantern {
+  name: "Lantern"
+  weight: 0.75
+  uses: []
+}

examples/lang/resources.ludic

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+# resources.ludic — L9: a registry whose entries live in a resource file. `from` names the file;
+# it is read when the program is compiled, every entry checked against the record (the schema),
+# and compiled in - so a mistake is a compile error at the resource file's line, and nothing parses
+# at start-up. A field whose type is a record, or a list of them, takes a bare `{ ... }`.
+#
+# Running it prints:  2 Axe 2 Split 10 0 1
+program Resources {
+  numbers float
+  property Use {
+    verb: string = ""
+    minutes: int = 0
+  }
+  property Tool {
+    key: string = ""
+    name: string = ""
+    weight: float = 0.0
+    uses: []Use = null
+  }
+  registry Tools of Tool as TL from "data/tools.lres"
+  entry {
+    let axe = Tools[TL_AXE]
+    print(`{TL_COUNT} {axe.name} {len(axe.uses)} {axe.uses[1].verb} {axe.uses[1].minutes} {len(Tools[TL_LANTERN].uses)} {tools_find("lantern")}`)
+  }
+}

examples/rejected/data/bad_tools.lres

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+axe {
+  name: "Axe"
+  weight: "heavy"
+}

examples/rejected/resource_field.ludic

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+# L9: a resource file's entries are checked against the record, at the file's own line
+program ResourceField {
+  numbers float
+  property Tool {
+    key: string = ""
+    name: string = ""
+    weight: float = 0.0
+  }
+  registry Tools of Tool from "data/bad_tools.lres"
+  entry { print(TOOLS_COUNT) }
+}

examples/rejected/resource_missing.ludic

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+# L9: a registry's resource file must exist
+program ResourceMissing {
+  property Tool { key: string = "" }
+  registry Tools of Tool from "data/no_such.lres"
+  entry { print(TOOLS_COUNT) }
+}