fix(core): Clear contexts on Scope.clear()

[runningcode]

📜 Description

Scope.clear() reset every field on the scope except contexts, so anything set via setContexts(...) survived a clear(). The root cause is that Contexts had no clear() method (unlike the tags, extra, and fingerprint collections that clear() already resets), so contexts were simply left untouched.

This PR:

• Adds Contexts.clear().
• Overrides clear() in CombinedContextsView to delegate to the default context, consistent with how put/remove already delegate (otherwise clear() on the view would no-op against its always-empty inherited storage).
• Clears contexts in Scope.clear() and notifies scope observers with the now-empty contexts, so persisted scopes (e.g. Android's scope-on-disk used for native crashes) stay in sync — matching what setContexts/clearBreadcrumbs already do.

💡 Motivation and Context

Reported while adding the scopes API to the Godot Engine (hybrid) SDK: clear() cleared everything except contexts, forcing a manual workaround that removes each context key by hand.

Fixes GH-5894
Fixes JAVA-683

💚 How did you test it?

Added unit tests:

• ContextsTest — clear() empties the contexts.
• CombinedContextsViewTest — clear() clears only the default context.
• ScopeTest — extended the reset test to cover contexts, plus a new test verifying clear() notifies scope observers with empty contexts.

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

Hybrid SDKs (e.g. Godot) can drop their manual context-clearing workaround once this ships.

[linear-code]

JAVA-683

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.52.0 (1)	release

⚙️ sentry-android Build Distribution Settings

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	318.40 ms	365.31 ms	46.91 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
d15471f	303.49 ms	439.08 ms	135.59 ms
b750b96	408.98 ms	480.32 ms	71.34 ms
17a0955	372.53 ms	446.70 ms	74.17 ms
d217708	355.34 ms	381.39 ms	26.05 ms
5b1a06b	310.56 ms	362.79 ms	52.22 ms
fcec2f2	311.35 ms	384.94 ms	73.59 ms
62b579c	349.26 ms	426.26 ms	77.00 ms
5f14e5d	325.76 ms	368.32 ms	42.56 ms
48277cd	320.38 ms	379.90 ms	59.52 ms
a416a65	295.53 ms	373.74 ms	78.21 ms

App size

Revision	Plain	With Sentry	Diff
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
b750b96	1.58 MiB	2.10 MiB	533.19 KiB
17a0955	1.58 MiB	2.10 MiB	533.20 KiB
d217708	1.58 MiB	2.10 MiB	532.97 KiB
5b1a06b	0 B	0 B	0 B
fcec2f2	1.58 MiB	2.12 MiB	551.51 KiB
62b579c	0 B	0 B	0 B
5f14e5d	1.58 MiB	2.19 MiB	620.00 KiB
48277cd	0 B	0 B	0 B
a416a65	1.58 MiB	2.12 MiB	555.26 KiB

[markushi]

LGTM!