docs(readme): restructure the support matrix into a presence overview

[saitota]

Summary

The single dense matrix was hard to read, so I tried restructuring it. Sharing as a proposal — please judge whether it's worth merging.

• Reduced it to a presence overview (✅ / blank): readers first want to know "is my tool supported?", not the full scope breakdown.
• Split AI Coding Tools from Open Standards (AGENTS.md, Agent Skills).
• Moved --targets values and mode details (project / global / simulated) to the Supported Tools reference, which already has that table.
• Kept the ⚠️ Deprecated markers and the Deprecation notes section as-is.

Note

The matrix was missing 3 entries the code already supports. Synced both README.md and docs/reference/supported-tools.md to the implementation: kilo × subagents/hooks, kiro × hooks.

If this table is updated by any automated/agentic flow when adding a tool, let me know — I'd like to avoid breaking that.

Test plan

• Overview matches the feature → tool registries in src/features/*/ (29 targets incl. open standards)
• oxfmt --check / cspell

[dyoshikawa]

Thanks for taking this on — the dense matrix really was hard to scan, and the presence-overview idea reads a lot better. The Kilo subagents/hooks correction is a genuine find too.

A couple of things to sort before this can merge. The branch is based on an older main, so as-is it reverts the Antigravity 2.0 split (antigravity-ide / antigravity-cli) and drops the deprecation markers — a rebase should clear that up. The bigger open question is AGENTS.md and AgentsSkills: the description says they moved into an Open Standards section, but that table isn't in the diff, so right now they just disappear. And since you're correcting Kilo, docs/reference/supported-tools.md needs the same edit to stay in sync.

On the design call itself, dropping the project/global/simulated nuance from the README in favor of the reference link is reasonable, but that's a maintainer judgement — I'd let dyoshikawa weigh in on losing the at-a-glance mode info. Left a few inline notes on the specific spots.

[dyoshikawa]

This branch looks like it's based on an older main. Since the merge base, main split Antigravity into antigravity-ide and antigravity-cli (Antigravity 2.0), and both support mcp and hooks. Collapsing them back into a single "Google Antigravity" row with mcp/hooks blank drops two rows and reads as a regression against current main. The ⚠️ deprecation markers on Gemini CLI and Antigravity also disappear here. Could you rebase on latest main and re-derive the table from the current one?

[dyoshikawa]

The description mentions splitting AI Coding Tools from Open Standards (AGENTS.md, Agent Skills), but I don't see an Open Standards table in the diff — the agentsmd and agentsskills rows are just removed. Both are still valid --targets (src/types/tool-targets.ts) and present in the docs reference table, so they vanish from the README entirely. Could you add the Open Standards table you mentioned, or keep these two in the matrix?

[dyoshikawa]

Marking Kilo subagents/hooks as ✅ is correct — KiloSubagent and KiloHooks are both registered, so the README was genuinely lagging here. Nice catch. One follow-up: docs/reference/supported-tools.md still shows these blank, and the project guidelines ask for README and docs to stay in sync, so it'd be good to update that file in the same PR.

[saitota]

Thanks for the review! Addressed all three:

• Rebased onto latest main
• Restored the Open Standards table (AGENTS.md, Agent Skills) to match the PR description.
• Synced docs/reference/supported-tools.md with the same kilo × subagents/hooks correction.

[dyoshikawa]

@saitota Thank you!