Clarify setup tool example: --install applies to every tool

The README's "you can also validate or install" block showed OpenCode
twice (once without --install, once with) while Hermes and Pi appeared
only once. A reader could reasonably conclude that OpenCode has a
two-step install flow Hermes/Pi don't. In reality --install is a flag on
setup tool itself and works identically across opencode, claude-code,
codex, openclaude, hermes, pi.

Also collapse the README compatibility matrix to a quick-scan support-
depth table that points at docs/wiki/Tool-Adapters.md as the single
source of truth. The two matrices were already drifting (README had a
5-column shape; Tool-Adapters has the 11-row capability matrix from the
v0.1.0 docs pass).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: JRS1986

README.md

@@ -105,13 +105,20 @@ ignored template and fill it on your machine:
 coding-scaffold credentials --target . --format env
 ```
 
-You can also validate or install the coding tool directly:
+You can also validate or install a coding tool directly. The default behavior validates that the
+tool is on `PATH` and configures the scaffold for it; add `--install` to install a missing tool
+without a second prompt (useful for prepared dev containers):
 
 ```bash
+# Validate + configure (works for any tool):
 coding-scaffold setup tool --tool opencode
-coding-scaffold setup tool --tool opencode --install
+coding-scaffold setup tool --tool claude-code
+coding-scaffold setup tool --tool codex
 coding-scaffold setup tool --tool hermes
 coding-scaffold setup tool --tool pi
+
+# Same command, but install if missing:
+coding-scaffold setup tool --tool opencode --install
 ```
 
 Optional add-ons use the same pattern:
@@ -331,16 +338,21 @@ coding-scaffold setup tool --tool pi
 coding-scaffold tools adapt --target ~/dev/my-project --tool pi
 ```
 
-### Compatibility Matrix
-
-| Tool | Generated by CodingScaffold | Native strengths | Routing stance | Support level |
-| --- | --- | --- | --- | --- |
-| OpenCode | `opencode.json`, `.opencode/agents/`, `.opencode/commands/` | providers, local models, agents, commands, permissions | recommendation, static profiles, optional gateway routing | deep/default |
-| Claude Code | `CLAUDE.md`, `.claude/settings.json`, commands, reviewer agent | project settings, permissions, slash commands, MCP, subagents | guidance and native profile choice | native config |
-| Codex | `AGENTS.md`, `.codex/config.toml`, `.codex/skills/` | layered instructions, approval modes, local CLI workflow | guidance and native model choice | native config |
-| OpenClaude | `.coding-scaffold/OPENCLAUDE.md` | OpenAI-compatible profiles, MCP, slash commands | guidance and manual profile choice | lightweight |
-| Hermes | `.coding-scaffold/HERMES.md` | memory, skills, MCP, messaging, backend choices | guidance and tool-native setup | lightweight |
-| Pi | `.coding-scaffold/PI.md` | project instructions, sessions, slash commands, extensions | guidance and tool-native setup | lightweight |
+### Support Depth At A Glance
+
+| Tool | Support depth |
+| --- | --- |
+| OpenCode | deep (full config, agents, commands, RouteLLM-ready) |
+| Claude Code | native config (`CLAUDE.md`, `.claude/`, reviewer agent) |
+| Codex | native config (`AGENTS.md`, `.codex/`, skills) |
+| OpenClaude | guidance (`OPENCLAUDE.md`) |
+| Hermes | guidance (`HERMES.md`) |
+| Pi | guidance (`PI.md`) |
+
+For the full capability-by-capability breakdown (install support, permissions, MCP, local models,
+cloud providers, static profiles, runtime routing, etc.) see the
+[compatibility matrix in Tool Adapters](docs/wiki/Tool-Adapters.md#compatibility-matrix) — that's
+the single source of truth; this table is a scannable summary.
 
 ## Knowledge Base