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.

docs/decisions/0001-kernel-base.md

@@ -1,4 +1,4 @@
-# ADR 0001 — Kernel Forward-Port
+# ADR 0001: Kernel Forward-Port
 
 **Status:** Accepted (2026-08-25). Supersedes the README's original plan44/6.6 goal.
 
@@ -18,7 +18,7 @@ deltas as a reviewable patch series in `patches/`.
 - Done and **hardware-verified on `warden-c8a3`**: clk, pinctrl, eMMC, GMAC, TRNG,
   OTP, SARADC/TSADC, RTC, USB host, PWM/backlight, VOP display, GT911 touch, AIC8800
   wifi, RGA, I2S audio, HPMCU mailbox, open NPU driver, PVTM.
-- **uClibc stays load-bearing** — RGA/MPP/ISP/NPU userspace ship as uClibc-only
+- **uClibc stays required**: RGA/MPP/ISP/NPU userspace ship as uClibc-only
   blobs; a glibc swap breaks media (flare-edge #51, wontfix). Any kernel bump
   inherits this.
 - Kernel bumps risk struct-ABI breaks for out-of-tree modules (the AIC8800/VLAN