chore(maestro): retarget installer, e2e harness, and docs at unified maestro binary (NAP-245)

- Installer: one `cargo install maestro` instead of two; ExecStart becomes
  `~/.cargo/bin/maestro daemon`; user unit renamed `maestrod.service` →
  `maestro.service`; configure step is `maestro daemon configure`.
- E2E harness: both `Daemon` and `Registry` subprocess wrappers shell out to
  the unified `maestro` binary with the appropriate subcommand.
- State dir: `~/.local/state/maestrod` → `~/.local/state/maestro`.
- Docs: CLAUDE.md repo layout, design spec repo layout + "Daemon (`maestro daemon`)"
  heading, INSTALL.md (full rewrite of CLI references + new thin-builds section).

CLAUDE.md

@@ -12,19 +12,25 @@ Linear project **Maestro** under team **Naps62**. Issues `NAP-211..218` cover th
 
 `.claude/linear.json` wires `/yolo` and `/work` to this project — they pick from "available now" (status backlog/pending, not blocked).
 
-## Repo layout (target)
+## Repo layout
 
-Cargo workspace, populated incrementally starting with NAP-211:
+Cargo workspace. NAP-245 unified the per-binary crates behind a single
+`crates/maestro/` umbrella that ships the `maestro` binary with feature gates
+(`cli` / `daemon` / `registry`, default = all three). The library crates kept
+their existing shape; only the per-binary `main.rs` files were retired.
 
 ```
 crates/
+├── maestro/             # umbrella binary `maestro` (cli + daemon + registry, feature-gated) (NAP-245)
 ├── maestro-protocol/    # shared wire types (NAP-211)
-├── maestro-daemon/      # per-host tmux wrapper + WS endpoints (NAP-212, NAP-214)
-├── maestro-registry/    # always-on phone book + HTTP API (NAP-213, NAP-215)
-├── maestro-cli/         # `maestro list/spawn/attach/kill` (NAP-216)
+├── maestro-config/      # shared on-disk config schema (NAP-233)
+├── maestro-cli/         # `maestro list/spawn/attach/kill/policy` dispatch (NAP-216)
+├── maestro-daemon/      # `maestro daemon` — tmux wrapper + WS endpoints (NAP-212, NAP-214)
+├── maestro-registry/    # `maestro registry` — phone book + HTTP API (NAP-213, NAP-215)
+├── maestro-web/         # standalone `maestro-web` browser UI (NAP-241, NAP-249)
 ├── maestro-installer/   # `maestro-install` wizard: cargo install + systemd (NAP-225)
 └── maestro-e2e/         # cross-process integration tests (NAP-217)
-web/                     # browser client (NAP-218, plan 2)
+web/                     # browser SPA (NAP-218)
 ```
 
 See `docs/INSTALL.md` for end-user install instructions.