Close pass four: undetented host curve read, LiveValues guard, ordering assert, static-lane fix, docs

Points toPlain's exponent arm at the undetented curve map so host reads
match the editor; adds a sizeof guard plus field-poison test for
LiveValues::operator==; skips the model write when an automation value
hasn't moved; corrects five stale doc citations.

docs/PLAN.md

@@ -1321,8 +1321,8 @@ value semantics, any deck geometry, or the bake's reset *membership* (W3-T2's).
   that is genuinely DRIVING re-sends and so keeps outranking the restore, while a lane that sent
   one point and had it folded does not. That is the correct reading of the rule "a lane in
   read/write mode outranks a plug-in-side set" (stated in `docs/product/parameter-automation.md`
-  §7 as reasoning from the host's replay behaviour, not from a header — the SDK does not spell it
-  out). The second pass's unbounded latch made the claim true by making every later writer
+  §6.1 as reasoning from the host's replay behaviour, not from a header — the SDK does not spell
+  it out). The second pass's unbounded latch made the claim true by making every later writer
   permanently deaf; `shell/instrument/CLAUDE.md`'s Authority section is the model now.
   (c) **STILL OPEN, and it is the half the bundled `[verify, FIRST]` originally asked**: that
   REAPER calls `setState` (not `setComponentState`) on a single-component plug-in — a state