feat(v4): add cross runtime adapters

CHANGELOG.md

@@ -5,6 +5,40 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [4.0.0] · 2026-04-30
+
+### Added
+- **Cross runtime adapter layer**: OpenClaw remains the primary stack for Fleet, and v4 extends orchestration, monitoring, reliability judging, routing, and delta tracking across Claude Code, Codex, Cursor, Windsurf, Gemini CLI, and custom agent stacks. Four built in adapters ship with the release.
+- `lib/core/adapters.sh`: registry, dispatcher, validator, and parallel probe helper. Each adapter implements a six function contract (`describe`, `verified`, `required`, `health`, `info`, `version`) and must complete within `FLEET_ADAPTER_TIMEOUT` seconds (default 6).
+- `lib/adapters/openclaw.sh`: verified probe of OpenClaw gateways via `/health` with authenticated `/v1/models` fallback when a token is configured. Preserves v3 OpenClaw behavior exactly.
+- `lib/adapters/http.sh`: generic HTTP probe with `expectedStatus`, custom `method`, optional bearer token, repeatable `headers`, and an optional `versionUrl`.
+- `lib/adapters/docker.sh`: queries the local docker daemon for container `State.Status` and `State.Health.Status`. Degrades gracefully when the docker CLI is missing.
+- `lib/adapters/process.sh`: detects the presence of an OS process via `pgrep`. Marked inferred because there is no protocol level handshake.
+- `fleet adapters`: lists registered adapters, marks each as verified or inferred, shows which adapter applies to every configured agent and runtime entry.
+- `fleet runtime add <name> <type> [options]`: registers a new entry under the `runtimes` key in config without manual JSON editing. Validates required fields per adapter, refuses names already used by an agent, writes the config atomically with `chmod 600`.
+- `fleet runtime test <name>`: one off probe of any runtime or agent. Animated spinner runs while health, info, and version probes execute in parallel, then renders all three sections.
+- `fleet runtime list`: shows live status of every runtime, probed in parallel with an animated progress indicator on TTY output.
+- `fleet runtime rm <name>`: removes a runtime from the config, with explicit not found feedback.
+- `fleet policy`: shows, toggles, scopes, requires, relaxes, edits, clears, and previews the optional operator constitution.
+- Optional `constitution` config block: prepends customizable operator rules to `fleet task`, `fleet parallel`, and `fleet steer` dispatches, with optional required mode that blocks scoped dispatches when rules are disabled or empty.
+- `runtimes` key in config: optional array of entries with at least `name` and `adapter`. Backward compatible: configs without the key behave exactly like v3.
+- User adapter directory: drop a custom `<type>.sh` file into `~/.fleet/adapters/` (or override via `FLEET_ADAPTERS_DIR`) and it is auto loaded with the same six function contract as the built ins.
+- `FLEET_ADAPTER_TIMEOUT` and `FLEET_ADAPTERS_DIR` environment variables documented in README and `_meta.json`.
+- `examples/cross-runtime/config.json`: full mixed runtime example covering openclaw, http, docker, and process adapters.
+
+### Changed
+- `bin/fleet`: routes `adapters` and `runtime|runtimes` subcommands, sources `lib/core/adapters.sh` alongside the other core libraries, exports `FLEET_ROOT`. Help text adds a CROSS RUNTIME section.
+- `fleet agents`: a new Runtimes section renders all v4 entries with adapter, endpoint, status, verified or inferred tag, and elapsed milliseconds. Probes run in parallel with an animated progress line on TTY output.
+- `fleet health`: a new Runtimes section probes every runtime entry through the adapter layer, in parallel.
+- `fleet sitrep`: tracks runtime state alongside agents and CI. Runtime status changes appear in the CHANGED section with `runtime <name>: <prev> → <new>` lines. Probing runs in a thread pool so a single slow runtime does not stall the sitrep.
+- `templates/configs/full.json`: includes a runtimes block with one example per adapter type. `templates/configs/minimal.json` reserves the `runtimes` key.
+- `_meta.json`: bumped version to 4.0.0, added `FLEET_ADAPTER_TIMEOUT` and `FLEET_ADAPTERS_DIR` to optional env vars, added the user adapter directory and runtimes config to permissions reads.
+
+### Backward Compatibility
+- Configs from v1 through v3 work without changes. Entries under `agents` continue to use the openclaw adapter by default. The runtime layer is purely additive.
+
+---
+
 ## [3.0.5] · 2026-04-30
 
 ### Fixed