docs(harnesses): summarize the 2026 landscape of AI agent harnesses (closes #95)

[d-morrison]

Important

Merge #173 first --- this PR is stacked on its branch (docs/claude-code-other-models) because the new section cross-references @sec-ai-claude-code-other-models. GitHub retargets this PR to main when #173 merges.

Closes #95

Adds a coding-agents section, chapters/ai-tools/ai-harness-landscape.qmd, mapping the harness landscape as of August 2026 and condensing the research summary in #95:

• the model-plus-harness framing and benchmark saturation
• terminal-first and editor-integrated harnesses (two linked tables), the autonomous and cloud tier, and the minimalist counter-trend
• the open-source versus proprietary split, local-model stacks, and the general agent-framework layer
• a job-to-harness selection table

Every volatile figure, ownership claim, and corporate event is dated and attributed to the summary in a leading callout. The adjacent inconsistency about Gemini CLI in two older fragments is tracked as #175 rather than fixed here.

🤖 Generated with Claude Code

https://claude.ai/code/session_01GMS285msTfSxnF4Cy9RkTE

[d-morrison]

Round 1 disposition, pushed as b645180: Addressed. The Pi placing now reads eighth, links the author's December 2025 write-up, and drops the "behind only the reference agent" clause. The source summary in #95 carried the wrong figure; a correction is noted there.

Posted by Claude Code (AI agent) --- not written by a human.

---

Generated by Claude Code

[Copilot]

🟡 Changes recommended

It introduces broken relative links and a lychee exclusion that doesn’t match the linked URL form, plus a factual inconsistency with the cited issue #95.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR adds a new “Harness Landscape in 2026” documentation section to the wai Quarto site, summarizing the August 2026 state of AI agent harnesses and how to choose among them (per issue #95).

Changes:

• Add a new harness-landscape chapter fragment and include it from chapters/coding-agents.qmd.
• Extend the spelling WORDLIST with new proper nouns/terms used in the added section.
• Add a lychee link-check exclusion for Amp’s homepage.

File summaries

File	Description
lychee.toml	Adds an exclusion intended to avoid lychee failures on Amp’s homepage.
inst/WORDLIST	Adds new allowed words used by the new harness-landscape section.
chapters/coding-agents.qmd	Adds a new top-level section and includes the new landscape fragment.
chapters/ai-tools/ai-harness-landscape.qmd	New content describing the 2026 harness landscape, including comparison tables and selection guidance.

Review details

Suppressed comments (1)

chapters/ai-tools/ai-harness-landscape.qmd:160

• Same relative-path issue as earlier in this file: agent-orchestration.qmd is one directory up from chapters/ai-tools/. This link will be broken as written.

[when orchestration helps](agent-orchestration.qmd#sec-orch-when) makes the same case for this lab's own use.

• Files reviewed: 4/4 changed files
• Comments generated: 3
• Review effort level: Lite

---

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[d-morrison]

Copilot round dispositions (head 7b939f9):

• Rebutted: the two agent-orchestration.qmd#sec-orch-when links. The fragment is included from chapters/coding-agents.qmd, so links resolve from chapters/, matching the sibling fragments; the link checker passed on this head.
• Rebutted: the ampcode.com lychee exclusion. The link checker passed with this exclusion and the bare-host link in place.
• Addressed: the Pi citation's date label now states the post's own date (2025-11-30). Rebutted: the "2nd place" figure comes from issue summarize the current state of AI harnesses #95's summary, which was corrected on the issue after reading the author's post; the chapter's "eighth" is the sourced figure.

Posted by Claude Code (AI agent) --- not written by a human.

---

Generated by Claude Code

[Copilot]

🟢 Approval recommended

The changes are documentation-focused and low-risk, with only minor maintainability nits noted.

Review details

Suppressed comments (1)

Previously missed (1) — in code that hasn't changed since the last review.

inst/WORDLIST:13

• auditability and auditable were added in the capitalized proper-noun section, but the WORDLIST is otherwise grouped with capitalized terms first and common lowercase terms later (e.g., agentic, aider, allowlist, ...). Keeping lowercase words in the lowercase section makes the list easier to scan and reduces avoidable merge churn.

• Files reviewed: 4/4 changed files
• Comments generated: 1
• Review effort level: Lite

[d-morrison]

Copilot round 2 dispositions (head e2c85cd):

• Addressed: the Amp lychee exclusion is anchored and escaped (^https://ampcode\.com/?$).
• Addressed (suppressed nit): auditability and auditable moved out of the capitalized block into the lowercase entries.

Posted by Claude Code (AI agent) --- not written by a human.

---

Generated by Claude Code

[Copilot]

🟢 Approval recommended

The changes are documentation-focused and consistent with existing cross-references, with only minor wording/grammar nits noted.

Review details

Suppressed comments (2)

Previously missed (2) — in code that hasn't changed since the last review.

chapters/ai-tools/ai-harness-landscape.qmd:16

• In the snapshot callout, this sentence mixes present and past tense ("arrive" vs "changed"/"reshuffled"), which reads like a grammar error. Consider keeping the tense consistent throughout the list.
  chapters/ai-tools/ai-harness-landscape.qmd:180
• This sentence is ungrammatical: "pain points toward" should be something like "pain points ... point toward" (or rephrase to avoid the double use of "points").

• Files reviewed: 4/4 changed files
• Comments generated: 0 new
• Review effort level: Lite

[Copilot]

🟡 Changes recommended

inst/WORDLIST contains unresolved Git merge-conflict markers that must be fixed before it can be safely merged.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Review details

Suppressed comments (1)

inst/WORDLIST:136

• Unresolved Git merge-conflict markers remain in the WORDLIST here as well. Remove the conflict markers and keep both sets of words so spellcheck can run and the list is valid.

<<<<<<< HEAD
Zsh
=======
Zechner
auditability

• Files reviewed: 4/4 changed files
• Comments generated: 1
• Review effort level: Lite

[Copilot]

🟢 Approval recommended

The documentation addition is internally consistent, integrates cleanly into the chapter structure, and includes the necessary supporting link/spell-check updates.

Review details

• Files reviewed: 4/4 changed files
• Comments generated: 0 new
• Review effort level: Lite

[github-actions]

👀 Claude Review Dispatched — run reviewing PR #174 at ad13fac.

[github-actions]

Claude finished review — View run

---

Everything checks out cleanly: no conflict markers anywhere, all @sec-* cross-reference targets exist, and no duplicate WORDLIST entries. This confirms the current head commit is byte-identical in content to what was reviewed and marked CLEAN in the last round.

Since the current head commit (ad13fac5878a3a7f92fdcee3943052a9518e8722) is exactly the same commit already reviewed and confirmed CLEAN in the 2026-09-01T21:07:27Z round ("Ready for merge — the blocking finding from the prior round..."), I re-verified the key facts independently rather than just trusting that summary:

• No merge-conflict markers anywhere in the tree (the previously-blocking issue in inst/WORDLIST stays fixed).
• All @sec-* cross-references in the new chapter (@sec-ai-harnesses, @sec-ai-coding-agent-platforms, @sec-ai-claude-code-other-models, @sec-ai-offline, @sec-ai-small-local-models, #sec-orch-when) resolve to labels that exist in chapters/coding-agents.qmd and chapters/agent-orchestration.qmd.
• inst/WORDLIST has no duplicate entries after the additions.
• lychee.toml's anchored ^https://ampcode\.com/?$ exclusion is unchanged from what was already reviewed and confirmed correct (regex-anchored per the file's own established convention).

No new commits exist on the PR since that round — gh pr view confirms headRefOid still equals ad13fac, the exact commit already reviewed. No new issues found.

Verdict

Ready for merge — head commit ad13fac5878a3a7f92fdcee3943052a9518e8722 is unchanged from the prior CLEAN round (2026-09-01T21:07:27Z), and independent re-verification of conflict markers, cross-reference resolution, and WORDLIST integrity confirms that verdict still stands.

Structured Review Data (JSON)

{
  "schema_version": "1.0",
  "reviewer": "claude",
  "commit_sha": "ad13fac5878a3a7f92fdcee3943052a9518e8722",
  "verdict": "CLEAN",
  "findings": []
}

Reviewed commit: ad13fac

[github-actions]

💰 Cost: $0.2877 (review) — run

[github-actions]

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