Modified a few things:

- Finished implementing relative date parsing and migrated date parsing
  from Flag(T) to it's own dedicated module. Additionally added a
  the ability to do "recursive" relative operations for time searching.
- Additionally made a Struct & Enum for containing relative operations
  around dates.
- Added additional checks in App & CommandNode(T) around checking
  env_vars of flags & checking for duplicate commands
- Added a CommandMeta record to contain the classname of the
  CommandNode(T)
- Seperated out all of the monolitic files (command_node.cr & file.cr).
  Moved the base classes and records into their own files in the dir
  with the same name of their generic counterparts.
- Fixed a number of macro related bugs around Command.argument &
  CliGen.add_global_flag
- My ass hurts from sitting here for hours and doing these changes and
  arguing with claude over what needs to be done. Fun tho.

utils/flag_matrix.cr

@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2026 Tristan Ancelet
+#
+# Manual harness for flag resolution + validation across every source a value
+# can arrive from. Driven by ./utils/flag_matrix.sh; see that script for the expected
+# results. Kept out of spec/ because each case needs its own process (env vars
+# must be set before startup).
+#
+# ENV VAR NAMING - the two kinds of flag derive their names differently:
+#
+#   global flag     add_global_flag(..., long: "--retries")  ->  RETRIES
+#                   derived from the long flag, minus the leading dashes
+#
+#   command arg     class Greet; argument(level : Int32 ...)  ->  GREET_LEVEL
+#                   derived as <COMMAND>_<VAR>, see app/generate.cr
+#
+# The asymmetry is easy to trip over: exporting LEVEL=9 does nothing at all,
+# because the command argument is bound to GREET_LEVEL.
+
+require "cligen"
+
+CliGen.add_global_flag(Int32,
+  long: "--retries",
+  short: "-r",
+  description: "retry count (global, validated 0..10, env: RETRIES)",
+  default: 3,
+  validation: ->(v : Int32) : Bool { v >= 0 && v <= 10 }
+)
+
+@[CliGen::CommandInfo(description: "flag resolution matrix")]
+class Greet < CliGen::Command
+  argument(name : String = "world",
+    long: "--name",
+    description: "plain string, no validation (env: GREET_NAME)"
+  )
+
+  argument(level : Int32 = 1,
+    long: "--level",
+    description: "validated < 5 (env: GREET_LEVEL)",
+    validation: ->(v : Int32) : Bool { v < 5 }
+  )
+
+  private def retries : Int32
+    CliGen::GLOBAL_FLAGS
+      .find { |f| f.long_key == "--retries" }
+      .not_nil!
+      .as(CliGen::Flag(Int32))
+      .value!
+  end
+
+  def main
+    puts "retries=#{retries} level=#{@level} name=#{@name}"
+  end
+end
+
+CliGen::App.process