Add help screen, connection indicators, README and release builds (M7)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

SPECS.md

@@ -6,7 +6,7 @@ A terminal UI to search for movies and series, add them to Radarr / Sonarr, and
 - **TUI library:** [tview](https://github.com/rivo/tview) (on top of tcell)
 - **License:** MIT
 - **Module:** `git.stinnesbeck.com/nils/arr-tui`
-- **Status:** M6 done
+- **Status:** M7 done
 
 ## 1. Goals
 
@@ -193,7 +193,7 @@ The file should be created with mode `0600`; warn if it is more permissive. API
 - [x] **M4** — SABnzbd client and Downloads view (queue + history) with live updates and pause/resume/delete.
 - [x] **M5** — Radarr/Sonarr queues merged into the Downloads view.
 - [x] **M6** — Interactive release search (movies, then series seasons/episodes) and grab.
-- [ ] **M7** — Polish: help screen, error handling, README, release builds.
+- [x] **M7** — Polish: help screen (`?`/F9), per-service connection indicators, README, Makefile release builds, `--version`.
 - [ ] **M8+** — v0.2 features (library view, series drill-down).
 
 ## 10. Open Questions