bump to 0.9.8; add padded-canary build (app_version_padding_tests)

Canary re-proven on this base: reconstruct-from-components trips the
fixture checks; an unpadded fixture trips the non-vacuity assertion.
De-literalizes stale version examples in comments.

src/app_version.h

@@ -21,11 +21,17 @@
 // PURE MODULE: NO REAPER types, NO SWELL, NO vendor/ includes. Standard library
 // only. Builds and unit-tests without REAPER (mirror of bank_model / tail_control).
 //
-// Leading-zero fidelity (V1, Daniel-fixed): the displayed/stamped string is EXACTLY
-// "0.9.01" — two-digit zero-padded patch. That exactness is why the version STRING is
-// the authoritative artifact (sourced verbatim from the one CMake variable), not a
+// Leading-zero fidelity (V1, Daniel-fixed): the displayed/stamped string preserves the
+// configured version EXACTLY as written — padded and unpadded versions are both
+// legitimate (e.g. "0.9.8" and "0.9.80" are different versions; a "0.9.01" renders its
+// zero-padded patch verbatim). That exactness is why the version STRING is the
+// authoritative artifact (sourced verbatim from the one CMake variable), not a
 // reconstruction from numeric components — CMake's `project(VERSION)` may normalize a
 // numeric patch field, so we never round-trip the string through integers to render it.
+// Guarded against reconstruct-from-components regressions in app_version.cpp by
+// app_version_padding_tests (the padded canary build). The canary does NOT guard
+// against the CMakeLists.txt source-of-truth line being changed to a CMake variable
+// derivation — that case is guarded by the comment block at the top of CMakeLists.txt.
 
 #include <optional>
 #include <string>
@@ -48,20 +54,21 @@ Channel channel();
 // True on the beta build only. Convenience over channel() == Channel::Beta.
 bool isBeta();
 
-// The user-visible version render. Stable: EXACTLY the CMake string ("0.9.01"). Beta:
-// that string plus a plain "-beta" suffix ("0.9.01-beta") — a plain suffix, NOT a
-// git-describe decoration (V2, Daniel-fixed). This is what the show-version action and
-// the bank-panel readout display. It is NOT the ext-state stamp value (see stampVersion).
+// The user-visible version render. Stable: EXACTLY the configured CMake string. Beta:
+// that string plus a plain "-beta" suffix — a plain suffix, NOT a git-describe
+// decoration (V2, Daniel-fixed). This is what the show-version action and the
+// bank-panel readout display. It is NOT the ext-state stamp value (see stampVersion).
 const std::string& appVersion();
 
 // The ext-state STAMP value — the writing-version recorded into a saved project. This is
-// the NUMERIC TRIPLE ONLY ("0.9.01") on BOTH channels: it deliberately carries NO channel
-// suffix, so (a) parseVersion classifies it as Stamped when its own channel reads it back
-// (a "-beta"-suffixed stamp would classify as Unknown — the V4 stamp-classifiability
-// requirement), and (b) stable's stamp value is byte-identical regardless of the channel
-// build. The channel is carried by the ISOLATED namespace (see extStateNamespace), never
-// baked into the stamp. Distinct from appVersion() precisely so the display can say
-// "-beta" while the stamp stays classifiable and stable-identical.
+// the NUMERIC TRIPLE ONLY (the configured string, no channel suffix) on BOTH channels:
+// it deliberately carries NO channel suffix, so (a) parseVersion classifies it as
+// Stamped when its own channel reads it back (a "-beta"-suffixed stamp would classify
+// as Unknown — the V4 stamp-classifiability requirement), and (b) stable's stamp value
+// is byte-identical regardless of the channel build. The channel is carried by the
+// ISOLATED namespace (see extStateNamespace), never baked into the stamp. Distinct from
+// appVersion() precisely so the display can say "-beta" while the stamp stays
+// classifiable and stable-identical.
 const std::string& stampVersion();
 
 // The project ext-state namespace this channel reads and writes. Stable: "reasampler"