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.

tools/config-lint/README.md

@@ -2,7 +2,7 @@
 
 Static target-config gates: catches flash-time config faults the behavioural sim cannot: mistakes in the
 *memory map*, not the logic. The first check is the one that would have caught the
-**c8a3 brick** — a boot-loaded coprocessor firmware dropped at `0x40000`, which is
+**c8a3 brick**: a boot-loaded coprocessor firmware dropped at `0x40000`, which is
 a `reserved-memory` carve-out on Thunder-Boot boards but plain kernel RAM on the 86 Panel,
 so the MCU and the kernel fought over the same DRAM and the board hung before eth0.
 
@@ -15,7 +15,7 @@ Every address the idblock loader drops MCU firmware to must sit inside a
   hpmcu/mcu/amp entry) in `[LOADER_OPTION]`, with its `LOAD_ADDR` from
   `[LOADERn_PARAM]`.
 - **Reserved ranges** come from the devicetree: every `reg = <addr size>` inside a
-  `reserved-memory { … }` node.
+  `reserved-memory { ... }` node.
 
 A load outside all reservations is a failure (non-zero exit).
 
@@ -37,6 +37,6 @@ found; `2` = usage/IO error.
 
 The suite encodes the brick as a regression: the real Thunder-Boot `.ini`
 (Hpmcu @ `0x40000`) *fails* against a DT with no `rtos@40000` node and *passes*
-once the reservation is added — and the 86 Panel's non-TB loader (no boot-loaded MCU)
-always passes. See `../../docs/architecture.md` §5 and, for the hardware hazard,
+once the reservation is added, and the 86 Panel's non-TB loader (no boot-loaded MCU)
+always passes. See `../../docs/architecture.md` section 5 and, for the hardware hazard,
 the `boot-loaded-mcu-0x40000-hazard` note.