[Improvement] Add contributor docs, AI assistant rules, and fix helm-lint

[GiladShapira94]

📝 Description

This PR improves the contributor and AI-assistant developer experience for the MLRun CE repository.
It adds CONTRIBUTING.md (new file) and significantly expands AGENTS.md with a Quick-Start Dev Workflow, Component Dependency Map, and "How to Add a New Component" guide.
A .cursorrules file is introduced for Cursor IDE users, mirroring the conventions in AGENTS.md.
The make helm-lint command is fixed with --validate-maintainers=false and --helm-extra-args "--timeout 600s" flags, and a missing trailing newline in Chart.yaml that caused yamllint failures is resolved.

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🛠️Changes Made

• CONTRIBUTING.md (new) — contributor guide covering prerequisites, dev workflow, commit/PR title format, three testing levels (lint, dry-run, Kind e2e), and release process
• .cursorrules (new) — Cursor IDE rules mirroring AGENTS.md/CLAUDE.md conventions; includes manual equivalents of /render, /bump, /pr Claude Code skills
• AGENTS.md — added Quick-Start Dev Workflow, Component Dependency Map table, and "How to Add a New Component" step-by-step guide.
• CLAUDE.md — added @CONTRIBUTING.md import and Preferred Response Patterns section with Claude-specific behavioral rules
• Makefile — ct lint updated with --validate-maintainers=false --helm-extra-args "--timeout 600s" to prevent false lint failures on local dev
• charts/mlrun-ce/Chart.yaml — version bumped 0.11.0-rc.34 → 0.11.0-rc.35; fixed missing trailing newline (resolved yamllint new-line-at-end-of-file error)
• .gitignore — added .claude/settings.local.json (machine-specific, not for commit)
• charts/mlrun-ce/README.md — minor whitespace cleanup (extra blank line before "Using Kubeflow Pipelines")

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✅ Checklist

• I have tested the changes in this PR
• I confirmed whether my changes require a change in documentation and if so, I created another PR in MLRun for the relevant documentation.
• I confirmed whether my changes require a changes in QA tests, for example: credentials changes, resources naming change and if so, I updated the relevant Jira ticket for QA.
• I increased the Chart version in charts/mlrun-ce/Chart.yaml.
• I confirmed that the installation works both on a local Docker Desktop environment and on a real cluster when using the required
  prerequisites.
  • If installation issues were found, I updated the relevant Jira ticket with the issue and steps to reproduce, or updated the prerequisites documentation if the issue is related to missing or outdated prerequisites.
• If needed, update https://github.com/mlrun/ce/blob/development/charts/mlrun-ce/README.md with the relevant installation instructions and version Matrix.
• If needed, update the following values files for multi namespace support:
  • Admin values
  • User values Node Port
  • User values ClusterIP

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🧪 Testing

Changes are documentation and tooling only — no Kubernetes resources or chart values were modified.
make helm-lint was verified passing locally with the updated ct lint flags and the Chart.yaml trailing-newline fix.
No cluster deployment is required for this change.

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🚨 Breaking Changes?

• Yes (explain below)
• No