chore(release): prepare v0.6.0

Bump the version to 0.6.0 across pyproject, the package, the config, and
the panel, and add the 0.6.0 CHANGELOG entry: inbound external/internal PR
review with a CEO decision queue and supersede, the panel feature-flags
card, the required-cells decomposition gate, the CEO-rejected
coordination-root deadlock fix, the panel UI pass, and registry-image
deploy.

Also refresh the locked dependencies, update the release-tag examples in
the README and deployment docs, and correct the package docstring's agent
count to 22.

CHANGELOG.md

@@ -4,6 +4,29 @@ All notable changes to RoboCo are 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).
 
+## [0.6.0] - 2026-06-17
+
+### Added
+
+- **Inbound PR review — the org reviews, and can take over, pull requests it didn't open.** A new read-only `pr_reviewer` role (its own agent image and spawn manifest) discovers inbound PRs, reviews the diff adversarially, and posts a single complete change-request to the PR itself — no agent-to-agent chatter. It covers external / fork PRs, gated by an author allowlist, and — behind a second flag — internal org-repo PRs opened outside the agent task-flow (the org's own in-flight integration PRs are skipped, since a live task already owns their branch and they pass QA + PM review). Re-review is driven by the PR's head commit: an unchanged PR is skipped, new commits open a fresh review, so a long-lived PR is never re-spammed. External-PR review is enabled by default in the shipped compose (with human-confirm on); internal-PR review is off by default. Both are flippable from the panel.
+- **CEO decision queue + supersede for reviewed PRs.** Completed reviews surface in a PR-review queue in the panel (in-flight reviews are shown too, linking to the PR, so it never goes dark). From there the CEO can dismiss a review, or **supersede** the PR: the system cuts a roboco-owned branch off the contributor's commits and opens a Main-PM coordination task to finish and harden the work to our standards on that branch, open our own PR, and — once that replacement actually merges — close and link the contributor's PR. We never push to a contributor's fork.
+- **Feature-flags panel.** A Settings → Feature Flags card toggles env-gated subsystems (external / internal PR review, web research, the strategy engine, pitch provisioning, RAG auto-update, transcript pruning) from the panel instead of hand-editing environment variables. A toggle persists in the existing settings store and takes effect on the next backend restart; an unset flag falls back to its environment / config default, and secrets (API keys, tokens) are never surfaced to the client.
+- **Required-cells decomposition gate.** When a coordination task names the cells that must deliver it, the Main PM can no longer go idle having silently dropped one — `i_am_idle` is rejected until every named cell has a subtask, and the Main-PM prompt now insists on honoring explicitly-named cells. Inert until the marker is set, so existing flows are unaffected.
+
+### Changed
+
+- **Run from pre-built registry images.** A standalone registry compose runs the full stack — including every per-agent image, now extended to the Secretary and the PR-reviewer — from published images rather than a local build. Both deploy paths, the registry knobs, and measured idle / under-load resource usage are documented.
+- **The how-to guide is now a structured, multi-chapter walkthrough** under `docs/how-to/`, with a new chapter on the business workflow (charter → Cockpit → Secretary, and the research / strategy / PR-review toggles). The published reference docs (README, usage, deployment, CLAUDE) were refreshed against the current code, and a CI guard now keeps documentation prose single-line.
+
+### Fixed
+
+- **A CEO-rejected coordination root no longer deadlocks.** A product-linked coordination task the CEO sends back to needs-revision is re-dispatched to its owning PM (and the readiness gate now accepts a PM on a coordination root in that state), instead of sitting unowned forever because the developer dispatcher skipped it.
+- **Panel UI standardization + usability pass.** A panel-wide pass plus targeted fixes: the Settings grid layout, the Journals and Kanban scroll regions, the agent-list item, the Projects table, kanban cards whose text overflowed, the PR-review queue's empty state, and the Secretary chat composer buttons.
+
+### Internal
+
+- DB-backed and httpx-mocked test coverage for the inbound-PR read and lifecycle paths (ingest / dedup / claim / complete / supersede); a cyclomatic-complexity refactor of the git PR-creation and lifecycle-validation code to clear the xenon gate; and the cell-PM / main-PM role docs corrected to the real `delegate` signature and cross-linked to each other.
+
 ## [0.5.0] - 2026-06-16
 
 ### Added