chore: the editor config describes this repository, in ASCII

.clangd said the repository rides as a submodule in its consumers, which none
does, and removed three codegen flags only pureboot's loaders carry; its em
dashes are ASCII now. The settings.json comment built on the same premise goes,
and the oracle README states the variant rather than who chose it.

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

.clangd

@@ -1,13 +1,10 @@
-# Editor accommodations for the second frontend. No compilation database is
-# named here: this repo rides as a submodule in its consumers, and this file
-# travels with it — a consumer's own database then covers these sources, with
-# that project's loader flags. The checkout that is opened as a folder names
-# its build tree in .vscode/settings.json instead.
+# Editor accommodations for the second frontend: only what is true of the
+# code wherever it is built. The build tree is named in .vscode/settings.json.
 CompileFlags:
   Add:
     # clang has no 24-bit integer and GCC's are keywords, not macros, so the
     # editor needs a stand-in for avr::uint24_t. The next width up is the only
-    # one available — clang rejects _BitInt(24) on this target.
+    # one available - clang rejects _BitInt(24) on this target.
     - -D__uint24=unsigned long
     - -D__int24=long
     # clangd forwards the driver's system includes but not its own header
@@ -16,15 +13,12 @@ CompileFlags:
     - -D__STDC_LIMIT_MACROS
     - -D__STDC_CONSTANT_MACROS
     # isr::emit spells a vector number into [[gnu::signal(N)]], which clang
-    # rejects rather than ignores — enough of them in one TU to reach the
+    # rejects rather than ignores - enough of them in one TU to reach the
     # default limit of 19 inside the headers and truncate the parse.
     - -ferror-limit=0
   Remove:
-    # Codegen shaping the loader TUs carry and clang has no spelling for.
-    - -fira-algorithm=*
-    - -fno-split-wide-types
+    # Codegen shaping the policy tier carries and clang has no spelling for.
     - -fno-tree-ter
-    - -fno-ivopts
     - -fno-move-loop-invariants
     # The build promotes warnings for the compiler that has to be right about
     # them; in the editor the flag paints a second frontend's opinions in the