docs: ASCII typography and style normalization across all repo text

Replace every em dash with real punctuation (rewrites, not hyphen swaps)
in docs, code comments, scripts, configs, and the port records; convert
en dashes, curly quotes, ellipsis glyphs, arrows, and section signs to
ASCII; drop machine-writing tell phrases from living docs. ADR titles
now use a colon. The M2 bring-up DTS model string carried an em dash
into the patch series and its record echoes; fixed at both, and the full
series re-verified to apply cleanly onto pristine 6.18.46. One comment
in freshness.h deliberately names the em dash glyph the UI renders as
the unknown mark; that is data, kept as prose naming it.

Verified: cargo tests (sim, config-lint, rs485-bridge), shellcheck,
both driver MC/DC harnesses, patches-apply.

patches/README.md

@@ -6,8 +6,8 @@ patch applies cleanly onto pristine 6.18.46 (`git apply --check`), and the whole
 reproduces the 223-file / ~136K-line delta that boots and is hardware-verified on
 `warden-c8a3` (see `../kernel/rv1106-enablement/`).
 
-Build it with `../build/build-kernel.sh` (fetch pristine → apply these → configure
-with `../build/warden_defconfig` → `zImage` + `rv1106-warden.dtb`).
+Build it with `../build/build-kernel.sh` (fetch pristine -> apply these -> configure
+with `../build/warden_defconfig` -> `zImage` + `rv1106-warden.dtb`).
 
 ## The Series
 
@@ -43,4 +43,4 @@ subsystem. Licensing/origin of each block is tracked in
 
 Whitespace: `60-wifi-aic8800.patch` carries the vendor blob's trailing-whitespace
 verbatim; `git apply --whitespace=nowarn` (the build wrapper) accepts it. Do not
-re-flow vendor code — it must stay diffable against future vendor drops.
+re-flow vendor code; it must stay diffable against future vendor drops.