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/rsync.md

@@ -0,0 +1,102 @@
+# rsync — Fast, Resumable File Transfers
+
+## Problem
+
+Copying large files or directory trees between drives or servers is slow, fragile, and unresumable with `cp`. A dropped connection or a single error means starting over. You also want to skip files that already exist at the destination without re-copying them.
+
+## Solution
+
+`rsync` is a file synchronization tool that only transfers what has changed, preserves metadata, and can resume interrupted transfers. It works locally and over SSH.
+
+### Installation (Fedora)
+
+```bash
+sudo dnf install rsync
+```
+
+### Basic Local Copy
+
+```bash
+rsync -av /source/ /destination/
+```
+
+- `-a` — archive mode: preserves permissions, timestamps, symlinks, ownership
+- `-v` — verbose: shows what's being transferred
+
+**Trailing slash on source matters:**
+- `/source/` — copy the *contents* of source into destination
+- `/source` — copy the source *directory itself* into destination
+
+### Resume an Interrupted Transfer
+
+```bash
+rsync -av --partial --progress /source/ /destination/
+```
+
+- `--partial` — keeps partially transferred files so they can be resumed
+- `--progress` — shows per-file progress and speed
+
+### Skip Already-Transferred Files
+
+```bash
+rsync -av --ignore-existing /source/ /destination/
+```
+
+Useful when restarting a migration — skips anything already at the destination regardless of timestamp comparison.
+
+### Dry Run First
+
+Always preview what rsync will do before committing:
+
+```bash
+rsync -av --dry-run /source/ /destination/
+```
+
+No files are moved. Output shows exactly what would happen.
+
+### Transfer Over SSH
+
+```bash
+rsync -av -e ssh /source/ user@remotehost:/destination/
+```
+
+Or with a non-standard port:
+
+```bash
+rsync -av -e "ssh -p 2222" /source/ user@remotehost:/destination/
+```
+
+### Exclude Patterns
+
+```bash
+rsync -av --exclude='*.tmp' --exclude='.Trash*' /source/ /destination/
+```
+
+### Real-World Use
+
+Migrating ~286 files from `/majorRAID` to `/majorstorage` during a RAID dissolution project:
+
+```bash
+rsync -av --partial --progress --ignore-existing \
+  /majorRAID/ /majorstorage/ \
+  2>&1 | tee /root/raid_migrate.log
+```
+
+Run inside a `tmux` or `screen` session so it survives SSH disconnects:
+
+```bash
+tmux new-session -d -s rsync-migrate \
+  "rsync -av --partial --progress /majorRAID/ /majorstorage/ | tee /root/raid_migrate.log"
+```
+
+### Check Progress on a Running Transfer
+
+```bash
+tail -f /root/raid_migrate.log
+```
+
+---
+
+## Tags
+
+#rsync #linux #storage #file-transfer #sysadmin #dev-tools