ADFA-3604: Fix Gson model classes and JDI debugger connector stripped by R8 (#1615)

* ADFA-3604: Fix Gson model classes stripped by R8 (6th shrink bug)

Found via a "Failed to load template archive ... Abstract classes can't
be instantiated!" error on-device. Same root cause as the other shrink
bugs fixed in this branch: Gson deserializes these classes only via
reflection (gson.fromJson(..., X::class.java)), never a direct `new`
R8 can trace, so it strips the constructor and Gson's runtime then
reports the class as abstract.

Fixes templates-impl's TemplatesIndex/TemplateJson/etc., and two more
instances found by auditing every gson.fromJson call site in the repo:
OpenedFilesCache/OpenedFile (no prior rule at all) and the breakpoint
persistence models.

Verified on-device: templates load cleanly, zero FATAL EXCEPTION in
logcat, Kotlin project init still succeeds.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* ADFA-3604: Fix JDI debugger connector stripped by R8 (7th shrink bug)

Found via a "Network access error" dialog on-device -- misleading, since
the app's debug-connect failure handler always appends a network-access
suggestion regardless of actual cause. The real error was buried in
logcat: "java.lang.Error: no Connectors loaded" from
com.sun.tools.jdi.VirtualMachineManagerImpl, caused by a
ServiceConfigurationError failing to instantiate
SocketAttachingConnector/SocketListeningConnector. Same root cause as
the other shrink bugs: JDI loads these via ServiceLoader, which R8
can't trace, so it stripped their no-arg constructors.

This exact fix was already anticipated and left commented out in this
file ("Initial rules to enable when R8 is shrinking to address
exceptions") from before shrinking was ever genuinely enabled -- just
needed uncommenting now that it is.

Verified on-device: JDWP listener starts successfully, no dialog, zero
FATAL EXCEPTION in logcat.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* ADFA-3604: Fix comment positional reference in proguard-rules.pro

The Gson keep-rule comment said the templates.impl.zip rule was
"above" when it's actually below in the file.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

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Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

Author: davidschachterADFA