chore: scrub named other-CLI references from the codebase

[Vasanthdev2004]

What

Scrub every named other-CLI reference out of the codebase and replace it with neutral phrasing. Two motivations:

1. Identity leak. AGENTS.MD described Zero as "in the same family as Claude Code, Codex, and Droid." Since AGENTS.MD is injected into the model as project context, the agent parroted that line verbatim when asked "who are you?" — naming other agents in its own identity.
2. Comments + PRD. A handful of doc comments and the PRD named specific other CLIs as the thing a behaviour was "matching".

Changes

• AGENTS.MD — Zero is now described on its own terms ("an open-source terminal coding agent"), no comparison.
• internal/tui/rendering.go, model.go, session_controls.go (+ test) — doc comments that named other CLIs now say "comparable terminal agents"; the existing generic "reference agents/TUIs" phrasing is unchanged. Comment-only, no behaviour change.
• docs/PRD.md — target/vision use generic "multi-provider terminal agents" instead of a named product. Claude Code and Cursor are kept as legitimate public-competitor positioning.

Not touched (intentionally)

• The ChatGPT Codex provider (internal/providers/openai/codex*.go) keeps its name — that's a real product Zero connects to, not a reference to another tool's source.
• The "factory" pattern code (factory.go, ClientFactory) — ordinary software term.

Verification

go build ./... + gofmt clean. A tracked-file sweep for opencode|openclaude|vix|droid returns nothing.

Summary by CodeRabbit

• Documentation
  • Updated Zero’s introductory text to remove comparisons and better highlight out-of-the-box basic task performance while keeping the “fully configurable surfaces” message.
  • Revised PRD positioning language to generalize the target to other multi-provider terminal agents.
  • Refreshed related TUI comments to use consistent, non-specific terminology (no behavior changes).

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: ae8e024a-12ea-4df0-8380-d5393ddfe1a8

📥 Commits

Reviewing files that changed from the base of the PR and between 9fb2d3a and c1d3783.

📒 Files selected for processing (5)

• docs/PRD.md
• internal/tui/model.go
• internal/tui/rendering.go
• internal/tui/session_controls.go
• internal/tui/session_controls_test.go

✅ Files skipped from review due to trivial changes (5)

• internal/tui/session_controls.go
• internal/tui/rendering.go
• docs/PRD.md
• internal/tui/session_controls_test.go
• internal/tui/model.go

---

Walkthrough

Documentation and inline comments were updated to remove specific agent-name references and replace them with generalized wording about multi-provider terminal agents and configurable TUI behavior.

Changes

Documentation wording update

Layer / File(s)	Summary
Docs positioning wording AGENTS.MD, docs/PRD.md	The AGENTS introduction and PRD target/vision text were rewritten to remove named agent comparisons and use generalized multi-provider language.
TUI comment wording internal/tui/model.go, internal/tui/rendering.go, internal/tui/session_controls.go, internal/tui/session_controls_test.go	Several inline comments and one test comment were updated to remove specific agent-name phrasing while keeping the described TUI behavior unchanged.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

Possibly related PRs

• Gitlawb/zero#44: Also changes docs/PRD.md positioning and vision text in the same area of the document.
• Gitlawb/openclaude#1676: Also updates AGENTS.md guidance text in the same file family.

Suggested reviewers

• gnanam1990
• anandh8x

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the PR’s main change: removing named references to other CLI/agent products from docs and comments.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

---

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[github-actions]

Zero automated PR review

Verdict: No blockers found

Blockers

• None found.

Validation

• [pass] Diff hygiene: git diff --check
• [pass] Tests: go test ./...
• [pass] Build: go run ./cmd/zero-release build
• [pass] Smoke build: go run ./cmd/zero-release smoke

Scope

Head: c1d378349830
Changed files (6): AGENTS.MD, docs/PRD.md, internal/tui/model.go, internal/tui/rendering.go, internal/tui/session_controls.go, internal/tui/session_controls_test.go

This deterministic review checks validation status and basic diff hygiene. A human reviewer still owns product judgment and design quality.