docs(agents): Remove duplicated agent rule files

[runningcode]

📜 Description

Removes two redundant agent rule files and consolidates the rule index into AGENTS.md.

• .cursor/rules/coding.mdc — reduced to a pointer at AGENTS.md. Its "Contributing Guidelines", "Coding rules", "Useful Resources", and "Key Commands" sections were near-verbatim duplicates of sections already in AGENTS.md, including the Google Truth paragraph in full. The file stays (with alwaysApply: true) so Cursor still has an entry point.
• .cursor/rules/overview_dev.mdc — deleted. It described each rule twice (a bullet list per rule, then a keyword→rule table), while every rule file already carries the same information in its own frontmatter description, which is what Cursor uses for auto-selection. It also instructed agents to use fetch_rules, a Cursor-only tool unavailable to other agents.
• AGENTS.md — the "STOP — Required Reading" block is replaced by a single table mapping each rule to when it applies.
• CLAUDE.md — updated to match, since it referenced the removed section.

Agents now read one file to get oriented instead of three.

💡 Motivation and Context

The required-reading chain made every session load AGENTS.md → coding.mdc → overview_dev.mdc before doing anything, and two of those three reads added no information. Duplicated guidance across files also drifts: the same rules were maintained in several places at once.

💚 How did you test it?

I did what Alex suggested, asked claude code which otel modes exist for java sdk? and then which context files did you use so far?, it printed

Two, both read in full at the start of this turn:

1. AGENTS.md — loaded per the instruction in CLAUDE.md (the project CLAUDE.md is injected into context automatically; I read AGENTS.md with the Read tool). It's what pointed me at the opentelemetry rule.
2. .cursor/rules/opentelemetry.mdc — the domain rule for sentry-opentelemetry-*, agent vs agentless, span processing, and OTLP.

📝 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.

#skip-changelog

[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