docs: Added Control Plane architecture diagram in Concepts page

[nthapa000]

What this PR does:
Adds Control Plane architecture diagram in Concepts page

Why we need it:
For better Control Plane architecture overview in v0.57.x

Which issue(s) this PR fixes:

Fixes #7042

v0.57.x

v1.0.x

Does this PR introduce a user-facing change?:

• How are users affected by this change: Not directly, a documentation change
• Is this breaking change: No
• How to migrate (if breaking change):

[github-actions]

👋 Hi @nthapa000, welcome to PipeCD and thanks for opening your first pull request!

We’re really happy to have you here

Before your PR gets merged, please check a few important things below.

---

Helpful resources

• Contributing guide: https://github.com/pipe-cd/pipecd/blob/master/CONTRIBUTING.md
• Development setup: https://github.com/pipe-cd/pipecd/blob/master/CONTRIBUTING.md#development

---

DCO Sign-off

All commits must include a Signed-off-by line to comply with the Developer Certificate of Origin (DCO).

In case you forget to sign-off your commit(s), follow these steps:

For the last commit:

git commit --amend --signoff
git push --force-with-lease

For multiple commits:

git rebase --signoff origin/master
git push --force-with-lease

---

Run checks locally

Before pushing updates, please run:

make check

This runs the same checks as CI and helps catch issues early.

---

💬 Need help?

If anything is unclear, feel free to ask in this PR or join us on the CNCF Slack in the #pipecd channel.
You can get your Slack invite from: https://communityinviter.com/apps/cloud-native/cncf

Thanks for contributing to PipeCD! ❤️

[nthapa000]

I have currently added the Control Plane Architecture diagram to the v1.0.x documentation also. However, I'm a little doubtful about whether I should keep it, since there's already a link that redirects users to the Control Plane Architecture Overview.

[Ayushmore1214]

Looks like an good approach to me! @rahulshendre thoughts ?

[rahulshendre]

@nthapa000, you were definitely attentive during the newcomers meet 🙌

[rahulshendre]

Overall LGTM, just copy it to docs dev as well
docs-dev is the working copy that becomes the next v0 release, or it'll be lost on the next v0 release

It doesn't overlap with the link, the diagram gives a quick visual on the concepts page, while the linked page goes deeper with the per-component breakdown, so they serve different purposes and the link is relevant.
I also pulled it locally and it renders cleanly on both v0.57.x and v1.0.x

[nthapa000]

Overall LGTM, just copy it to docs dev as well docs-dev is the working copy that becomes the next v0 release, or it'll be lost on the next v0 release

It doesn't overlap with the link, the diagram gives a quick visual on the concepts page, while the linked page goes deeper with the per-component breakdown, so they serve different purposes and the link is relevant. I also pulled it locally and it renders cleanly on both v0.57.x and v1.0.x

Thanks @rahulshendre for feedback, added in docs-dev

[rahulshendre]

LGTM 👍🏻
Thanks @nthapa000

[rahulshendre]

@mohammedfirdouss @eeshaanSA, PTAL when you get time

[rahulshendre]

@khanhtc1202 @mohammedfirdouss @eeshaanSA, PTAL when you have time

[khanhtc1202]

Thank you 👍

[github-actions]

Thank you for contributing to PipeCD, @nthapa000! The changes in this pull request will be part of the upcoming release!