docs: rename K8s Agent to Cluster Collector

[Sahil52sp]

"Agent" is already a customer-facing term for NudgeBee's autonomous AI (NuBi), so calling the passive in-cluster component an "agent" overclaims what it does and confuses scope in sales conversations. The in-cluster component only aggregates metrics, events, logs and traces and relays them out over a WebSocket — no LLM, no decision-making, no autonomy.

Renames the narrative across the installation docs so the install flow tells users to install the Cluster Collector rather than the agent:

• Sidebar label, page titles, headings and prose under installation/**
• Landing page, server docs and the K8s references in the Proxy Agent docs
• Adds a terminology note mapping the old name to the new one

Deliberately unchanged, so nothing a user types or clicks breaks:

• Helm repo/chart/release and the nudgebee-agent namespace
• Pod, service account and values key names (nodeAgent.*, agent.accessKey)
• URL paths, doc ids and the chore(deps-dev): bump @tsconfig/docusaurus from 1.0.7 to 2.0.2 in /doc-server #2-install-the-agent anchor, now pinned explicitly on the renamed heading
• Node Agent (eBPF DaemonSet) and Proxy Agent (Forager), which are separate components that keep their names
• Console labels the UI still shows: Agent Health, Agent URL, Agent Version — called out in a note rather than silently renamed

Verified with a production Docusaurus build (onBrokenLinks: throw).

Claude-Session: https://claude.ai/code/session_01GXgnUKdn8vXQn4oiXSMrDG

Summary

Briefly describe what this PR changes and why. Link related issues
(e.g., Closes #123).

Type of change

• Typo / minor wording fix
• New documentation page
• Update to existing documentation
• Build, CI, or tooling change
• Other (please describe)

Checklist

• I ran npm run build locally and the site builds without errors
• I ran npm run lint locally and lint passes
• Internal links work; new external links open the correct page
• My commits are signed off (DCO — git commit -s)
• I read CONTRIBUTING.md

Screenshots (if visual changes)

Additional notes

Anything reviewers should know — tradeoffs, follow-ups, things you
considered and rejected.

[gemini-code-assist]

Code Review

This pull request updates the documentation to rename the "NudgeBee Agent" (or "K8s Agent") to "Cluster Collector" across various installation, configuration, and troubleshooting guides. The review feedback correctly identifies a few instances where this renaming was over-applied: specifically, the third-party "Elastic Agent" was incorrectly renamed to "Elastic Collector," and references to the "Node Agent" (which is a distinct sub-component that retains the "agent" name) were mistakenly changed to "collector."

[gemini-code-assist]

Elastic Agent is the official name of the product by Elastic (often used with Fleet). Renaming it to "Elastic Collector" is incorrect and may confuse users. It should remain "Elastic Agent".

Suggested change

	2. Check data stream aliases if using modern Elastic Collector or Fleet:
	2. Check data stream aliases if using modern Elastic Agent or Fleet:

References

1. When writing documentation, always use the verbatim labels, feature flags, or UI strings as they appear in the product interface, even if they deviate from standard spelling or capitalization rules, to prevent confusing users who are trying to locate those elements.

[gemini-code-assist]

Since the Node Agent is a separate component that retains the "agent" name (and is not the Cluster Collector), referring to it as "the collector" here can be confusing. It should be referred to as "the node agent".

Suggested change

	| `LISTEN` | Address the collector listens on (`ip:port` or `:port`) | `0.0.0.0:80` |
	| `LISTEN` | Address the node agent listens on (`ip:port` or `:port`) | `0.0.0.0:80` |

[gemini-code-assist]

Since the PodMonitor scrapes the Node Agent pods (which are distinct from the Cluster Collector), referring to it as "the collector" here is confusing. It should be "the node agent".

Suggested change

	| **Duplicate series per pod with different labels** | Both a static scrape job and PodMonitor are active, scraping the collector twice with conflicting `instance` labels. Disable `nodeAgent.podmonitor.enabled: false`. |
	| **Duplicate series per pod with different labels** | Both a static scrape job and PodMonitor are active, scraping the node agent twice with conflicting `instance` labels. Disable `nodeAgent.podmonitor.enabled: false`. |