docs: remove em dashes from repo prose and forbid them going forward

- Rewrote em dash prose across the whole tree outside docs/reviews/
  (the historical reviews stay verbatim, matching the alktunnels and
  alktty precedent): src doc comments and inline comments (587),
  docs/architecture (319), docs/research + sdd_process (484), tests
  (361), tasks (899), fuzz (28), README/CHANGELOG/Cargo.toml (77),
  AGENTS.md (85), and the .opencode/agents prompts (109)
- Fenced content follows the precedent: comments, ASCII-diagram label
  separators, and template placeholders rewritten; wire data, JSON/BAST
  documents, byte diagrams, and transcripts survive verbatim; assert,
  expect, panic, error-display, and format message literals rewritten
  as prose; no code, fixture, or test data change
- src/rfc1928/LICENSE: the two dashes in alksocks' own provenance
  header rewritten; the MIT legal text untouched
- AGENTS.md adds Project Convention 18: no em dashes in prose; varied
  restructure, no spaced-hyphen substitutes, fenced prose rule, en
  dash numeric ranges exempt, docs/reviews/ exempt from the greps
- tasks/*.md frontmatter: the name values rewritten by the sweep are
  now quoted (a raw colon inside an unquoted YAML scalar parsed as
  null); taskgraph validate reports 37 tasks, no issues

Verification: cargo test; cargo clippy --all-targets -D warnings;
cargo fmt --check; cargo doc --no-deps; fuzz corpus replay
(cargo test --manifest-path fuzz/shared/Cargo.toml); wasm check and
clippy for wasm32-unknown-unknown with -D warnings; em dash grep over
the repo returns matches only in docs/reviews/ and the bast.md BAST
JSON data fence

docs/architecture/decisions/008-provider-defaults.md

@@ -1,9 +1,9 @@
-# ADR-008: Egress/Accept Provider Defaults — Local Socket and Composed (Direct Op)
+# ADR-008: Egress/Accept Provider Defaults: Local Socket and Composed (Direct Op)
 
 ## Status
 
-Accepted (2026-09-20, Phase 1; the A/B assembly-layer choice —
-OQ-SK-01's residue — with the composed vehicle settled by
+Accepted (2026-09-20, Phase 1; the A/B assembly-layer choice
+(OQ-SK-01's residue), with the composed vehicle settled by
 alktunnels 0.2.0 ADR-007)
 
 ## Context
@@ -11,12 +11,12 @@ alktunnels 0.2.0 ADR-007)
 OQ-SK-01's dialer-trait-vs-callback half is closed (ADR-004); what
 remained was the **default provider set**: where does the dial
 callback come from in the base crate's optional shapes? Option A
-(dial via alktunnels — the composed shape), Option B (dial directly
-— local TCP), Option C (injected dialer trait — rejected, ADR-004).
+(dial via alktunnels, the composed shape), Option B (dial directly,
+local TCP), Option C (injected dialer trait, rejected, ADR-004).
 alktunnels 0.2.0 removed Option A's blocker (the direct op
-`channels/tunnel/direct` is the dynamic-target channel — one open
+`channels/tunnel/direct` is the dynamic-target channel: one open
 per CONNECT target, what it was graduated for), and POC #2 measured
-its per-destination open cost (~0.8 ms, loopback) — fine for DNS +
+its per-destination open cost (~0.8 ms, loopback), fine for DNS +
 browsing.
 
 ## Decision
@@ -25,7 +25,7 @@ browsing.
   - **Local-socket providers** (behind the `local` feature): a real
     `TcpStream` dial (CONNECT), a real `UdpSocket` egress
     (ASSOCIATE, one socket per association, per-datagram
-    `send_to`/`recv_from` — no flow table; domain destinations
+    `send_to`/`recv_from`; no flow table; domain destinations
     resolve at the egress, the ssh `-D` semantic), a real
     `TcpListener` accept (BIND, ADR-007 variant 1). These are the
     faithful-RFC shapes and the simplest assembly story.
@@ -33,10 +33,10 @@ browsing.
     dial callback opens an alktunnels direct-op channel naming the
     target (`open_direct`, `Substrate::Tcp`/`Substrate::Udp`); the
     UDP table is a lazy destination→tunnel table (open on first
-    datagram, LRU-evict at a cap — POC #2's `ComposedEgress` shape).
+    datagram, LRU-evict at a cap, POC #2's `ComposedEgress` shape).
     Hub relaying is per-target terminate-and-re-produce
     (alkcall ADR-051).
-- **Neither provider is a dependency of the protocol layer** —
+- **Neither provider is a dependency of the protocol layer**;
   both are assembly-layer wiring (ADR-004); the features exist so
   the providers ship *in the crate* rather than forcing every
   deployment to hand-roll them. The feature gates and module
@@ -46,11 +46,11 @@ browsing.
   The feature-gated providers are convenience constructors over
   the same seams. A missing callback means that command refuses
   RFC-faithfully (`CommandNotSupported`-class reply), never a
-  panic — the command gate is the open handler's dispatch, and a
+  panic: the command gate is the open handler's dispatch, and a
   provider-less command is an unprovided capability, not an error
   condition.
 - **Per-target ACL is the composed variant's benefit** (each
-  destination rides its own `tunnel:direct`-governed channel —
+  destination rides its own `tunnel:direct`-governed channel,
   ADR-006); the local variant's target policy is the dial
   callback itself.