release: v2.4.0 — nano + micro editors, CI hardening, opencode 1.17.10 → 1.17.13

Promotes the Unreleased block to v2.4.0. Bundled contents:
- feat: nano + micro non-modal editors (d9ad634) — Dockerfile.base change → base rebuild
- ci: sh-vs-bash guard + base-latest digest promote, ported from pi-devbox (acb2096)
- feat: global gitignore baked into the image (6639ba5)
- opencode 1.17.10 → 1.17.13 (Dockerfile.variant)

Also registers .gitea/workflows/lint.yml in AGENTS.md's workflow list.
DOCKER_HUB.md unchanged (HUB_TEMPLATE untouched; --check passes).
Pre-flight: opencode-ai@1.17.13 confirmed on npm (== latest).

CHANGELOG.md

@@ -6,7 +6,22 @@ Tags follow **independent semver** (since `v2.0.0`) — they version *this image
 
 ---
 
-## Unreleased
+## v2.4.0 — 2026-07-01
+
+Minor release. Adds two **non-modal editors** (`nano` + `micro`) alongside
+nvim, ports **CI hardening** from pi-devbox (the sh-vs-bash workflow guard and
+the `base-latest` digest-based promote fix), bakes a **global gitignore** into
+the image, and bumps **opencode `1.17.10` → `1.17.13`**. Because
+`Dockerfile.base` changed (nano + micro), this release rebuilds the base image.
+
+### Changed
+
+- **opencode `1.17.10` → `1.17.13`** (three upstream patches). Highlights:
+  session snapshots + revert controls (1.17.11); MCP OAuth reconnect/refresh
+  fixes, a TUI yolo auto-approve mode, and better default small models
+  (1.17.12); forced reasoning mode for OpenAI-compatible reasoning models plus
+  a GitHub Copilot stale-response-ID fix (1.17.13). Full notes:
+  <https://github.com/anomalyco/opencode/releases>.
 
 ### Added