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/0003-standalone-repo.md

@@ -1,13 +1,13 @@
-# ADR 0003 — Standalone Repo
+# ADR 0003: Standalone Repo
 
 **Status:** Accepted (2026-08-25). Repo-visibility half superseded by ADR-0007
-(2026-08-30) — warden-sdk went public; the "private for now" consequence below
+(2026-08-30): warden-sdk went public; the "private for now" consequence below
 no longer holds. Original decision kept for the record.
 
 ## Context
 Our real SDK changes lived as uncommitted edits in a 2GB opaque vendor fork, with
-no CI, tests, or versioning of their own. The SDK requirement (future-features-2
-§SDK) calls for "its own repo, held to firmware standards."
+no CI, tests, or versioning of their own. The SDK requirement (future-features-2,
+SDK section) calls for "its own repo, held to firmware standards."
 
 ## Decision
 A **private** `warden-sdk` GitHub repo (now `blueflare-energy/bfe-core1106-sdk` and public
@@ -17,7 +17,7 @@ on a passing review run, green CI, and the maintainer's fresh explicit go-ahead.
 
 ## Consequences
 - flare-edge consumes this repo later (flared depending on `warden-sim`, drivers
-  built from here) — a separate, maintainer-gated integration step; flare-edge is not
+  built from here), a separate, maintainer-gated integration step; flare-edge is not
   edited by the SDK-completion effort.
 - Private for now (references bench devices / in-progress hardening); can be opened
   later once scrubbed, matching how `flare-deployment` is handled.