Rename Bits AI products (Chat, Investigation, Code, Agent Builder)

[dgreen15]

What

Updates all English documentation references to reflect the Bits product renames:

Old name(s)	New name
Bits Assistant, Bits AI Assistant	Bits Chat
Bits AI SRE	Bits Investigation
Bits Dev, Bits AI Dev, Bits AI Dev Agent, Bits Dev Agent	Bits Code
Agent Builder, Datadog Agent Builder	Bits Agent Builder

28 files changed in content/en/.

Scope & decisions

• Prose only. URLs, directory names (bits_ai_sre/, bits_ai_dev_agent/, actions/agents/), image filenames, anchors, and permission codes (e.g. bits_dev_write) are left unchanged to avoid broken links.
• Permission display names updated, codes preserved: "Bits Assistant Access" → "Bits Chat Access"; "Bits Dev Agent Write" → "Bits Code Write" (code stays bits_dev_write).
• Nav labels smoothed: "Bits AI > Assistant" → "Bits AI > Chat"; "Bits AI > Dev Agent" → "Bits AI > Code".
• Redundancy collapsed: "a Bits AI SRE investigation" → "a Bits Investigation" (not "...Investigation investigation").
• Left untouched: the umbrella brand Bits AI and the separate Bits AI Security Analyst product.
• English only — translated files (es/fr/ja/ko) are not included.

Follow-ups for reviewers

• Confirm the inferred nav menu item names ("Chat", "Code") match the actual UI.
• Screenshot content still shows old names; alt text was updated but images need re-capturing separately.

🤖 Generated with Claude Code

[github-actions]

⚠️ Possible site support note detected

The following files have a site-region shortcode at the top of the page that mentions a feature being "not available" or "not supported":

• content/en/security/code_security/static_analysis/_index.md
• content/en/tests/flaky_management/_index.md

Are you trying to document site support for a product? If so, the site-region shortcode is not the recommended approach. See the Documenting site support guide for the preferred method.

[dgreen15]

Superseded by #37117 (branch renamed to dgreen15/rename-bits-products so CI checks requiring a slash in the branch name run).