[Installer] Make the Inno Setup installer the default, with its failure hook.

COCKATRICE_WIN_INSTALLER now defaults to InnoSetup. NSIS stays selectable for
one release as the legacy fallback, and the two can still be built from one
tree and compared on a real upgrade.

The switches question from the previous commit is settled from Inno Setup's
source: the setup command line is an if/else-if chain over the switches it
knows, with no fallback that rejects the rest, so /R, /PID= and /D= are
ignored rather than refused. The client therefore sends one command line that
drives either installer:

- /R and /PID= for NSIS, which also needs /D= last and unquoted;
- /VERYSILENT and the CloseApplications set for Setup, which releases the
  mapped runtime DLLs through Restart Manager instead of waiting for a pid;
- /UPDATER as the client's own mark, read only by the Inno Setup script.

An older client that passes only the NSIS switches still installs; it walks
the wizard once instead of running silently.

The Sentry offer that AbortInstall carried is ported: a silent run the updater
launched, which began replacing files and never reached the end, offers to
send its log through the same helper. The helper is embedded with a [Files]
dontcopy entry and extracted at send time; a repeated [Files] section merges
with the generated one instead of being a compile error. Setup prefixes every
log line with a timestamp, so the helper's ABORT scan now allows that prefix.

CI installs Inno Setup next to NSIS, dumps ISCCOutput.log and the generated
script when the installer fails to compile, and --package NSIS|InnoSetup
selects the installer through the CMake option instead of adding a second
CPack generator to the run.

cmake/InnoSetup.install.iss

@@ -1,9 +1,11 @@
 ; Sections added to the setup script CPack's Inno Setup generator writes.
 ;
 ; Included through CPACK_INNOSETUP_EXTRA_SCRIPTS, which prepends this file to the
-; generated script. Only sections the generator never emits may appear here: it writes
-; [Files], [Dirs], [Icons], [Run] and [Registry] from the install() rules, and a second
-; section of one of those is a compile error. Behaviour belongs in InnoSetup.code.iss.
+; generated script. Repeating a section that the generator also writes is not an error: the
+; compiler re-tests every [Header] against the section it is collecting and enumerates the
+; lines of each occurrence (FoundSection in TSetupCompiler.EnumIniSection,
+; Compiler.SetupCompiler.pas), so the [Files] and [InstallDelete] below merge with the ones
+; built from the install() rules. Behaviour belongs in InnoSetup.code.iss.
 
 [InstallDelete]
 ; The previous version's runtime, whatever it was called. Replacing a DLL in place is not
@@ -21,3 +23,14 @@ Type: filesandordirs; Name: "{app}\Plugins"
 ; install (RemoveLegacyNSISRegistration in InnoSetup.code.iss); the binary itself has no
 ; business staying next to the new one.
 Type: files; Name: "{app}\Uninstall.exe"
+
+; The installer-log sender behind the failure hook in InnoSetup.code.iss. dontcopy embeds
+; the file in the setup image without installing it, and ExtractTemporaryFile pulls it out
+; into the temporary directory only when something went wrong - what the NSIS template did
+; by writing the same helper into $PLUGINSDIR. The path arrives from CMake as a public ISCC
+; macro defined only for a build that carries a Sentry DSN; without one there is nothing to
+; send, so nothing is embedded and the hook compiles out.
+#ifdef SentryHelperPath
+[Files]
+Source: "{#SentryHelperPath}"; Flags: dontcopy
+#endif