wiki: add dev-tools section with tmux, screen, and rsync articles

Add three new articles to 03-opensource/dev-tools/:
- tmux: persistent terminal sessions, background jobs, capture-pane
- screen: lightweight alternative, comparison table
- rsync: flags reference, resumable transfers, SSH usage

Update all indexes (SUMMARY, section index, main index, README).
Article count: 28 → 31. Remove tmux from writing backlog.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

03-opensource/dev-tools/screen.md

@@ -0,0 +1,76 @@
+# screen — Simple Persistent Terminal Sessions
+
+## Problem
+
+Same problem as tmux: SSH sessions die, jobs get killed, long-running tasks need to survive disconnects. screen is the older, simpler alternative to tmux — universally available and gets the job done with minimal setup.
+
+## Solution
+
+`screen` creates detachable terminal sessions. It's installed by default on many systems, making it useful when tmux isn't available.
+
+### Installation (Fedora)
+
+```bash
+sudo dnf install screen
+```
+
+### Core Workflow
+
+```bash
+# Start a named session
+screen -S mysession
+
+# Detach (keeps running)
+Ctrl+a, d
+
+# List sessions
+screen -list
+
+# Reattach
+screen -r mysession
+
+# If session shows as "Attached" (stuck)
+screen -d -r mysession
+```
+
+### Start a Background Job Directly
+
+```bash
+screen -dmS mysession bash -c "long-running-command 2>&1 | tee /root/output.log"
+```
+
+- `-d` — start detached
+- `-m` — create new session even if already inside screen
+- `-S` — name the session
+
+### Capture Current Output Without Attaching
+
+```bash
+screen -S mysession -X hardcopy /tmp/screen_output.txt
+cat /tmp/screen_output.txt
+```
+
+### Send a Command to a Running Session
+
+```bash
+screen -S mysession -X stuff "tail -f /root/output.log\n"
+```
+
+---
+
+## screen vs tmux
+
+| Feature | screen | tmux |
+|---|---|---|
+| Availability | Installed by default on most systems | Usually needs installing |
+| Split panes | Basic (Ctrl+a, S) | Better (Ctrl+b, ") |
+| Scripting | Limited | More capable |
+| Config complexity | Simple | More options |
+
+Use screen when it's already there or for quick throwaway sessions. Use tmux for anything more complex. See [tmux](tmux.md).
+
+---
+
+## Tags
+
+#screen #terminal #linux #ssh #productivity #dev-tools