feat: add flaskpaste plugin with paste/shorten commands

- PoW-authenticated paste creation and URL shortening via FlaskPaste
- !paste <text> creates a paste, !shorten <url> shortens a URL
- Module-level shorten_url/create_paste helpers for cross-plugin use
- Alert plugin auto-shortens URLs in announcements and history output
- Custom TLS CA cert support via secrets/flaskpaste/derp.crt
- No SOCKS proxy -- direct urllib.request to FlaskPaste instance

docs/CHEATSHEET.md

@@ -273,6 +273,16 @@ API keys: set `ABUSEIPDB_API_KEY` / `VIRUSTOTAL_API_KEY` env vars or
 configure in `config/derp.toml` under `[abuseipdb]` / `[virustotal]`.
 VT rate limit: 4 req/min. Email check: max 5, admin only.
 
+## FlaskPaste
+
+```
+!paste some text here             # Create paste, get URL
+!shorten https://long-url.com/x   # Shorten URL
+```
+
+Auto-shortens URLs in `!alert` announcements and history when plugin is loaded.
+Config: `[flaskpaste]` in `config/derp.toml` or `FLASKPASTE_URL` env var.
+
 ### Data Setup
 
 ```bash

docs/USAGE.md

@@ -131,6 +131,8 @@ format = "text"               # Log format: "text" (default) or "json"
 | `!abuse <ip> report <cats> <comment>` | Report IP to AbuseIPDB (admin) |
 | `!vt <hash\|ip\|domain\|url>` | VirusTotal lookup |
 | `!emailcheck <email> [email2 ...]` | SMTP email verification (admin) |
+| `!paste <text>` | Create a paste on FlaskPaste |
+| `!shorten <url>` | Shorten a URL via FlaskPaste |
 
 ### Command Shorthand
 
@@ -845,3 +847,49 @@ bad@example.com -- SMTP 550 User unknown (mx: mail.example.com)
 - Raw SMTP via SOCKS5 proxy: EHLO, MAIL FROM:<>, RCPT TO, QUIT
 - 15-second timeout per connection
 - Max 5 emails per invocation
+
+### `!paste` -- Create Paste
+
+Upload text to FlaskPaste and get a shareable URL.
+
+```
+!paste some long text here
+```
+
+Output format:
+
+```
+https://paste.mymx.me/abc12345
+```
+
+- PoW challenge (difficulty 20) solved per request
+- Content sent as JSON body to FlaskPaste API
+- No API key needed -- PoW is the auth mechanism
+- Raw content available at `<paste_url>/raw`
+
+### `!shorten` -- Shorten URL
+
+Shorten a URL via FlaskPaste's URL shortener.
+
+```
+!shorten https://very-long-url.example.com/path/to/resource
+```
+
+Output format:
+
+```
+https://paste.mymx.me/s/AbCdEfGh
+```
+
+- URL must start with `http://` or `https://`
+- PoW challenge (difficulty 20) solved per request
+- Also used internally by `!alert` to shorten announcement URLs
+
+### FlaskPaste Configuration
+
+```toml
+[flaskpaste]
+url = "https://paste.mymx.me"    # or set FLASKPASTE_URL env var
+```
+
+TLS: custom CA cert at `secrets/flaskpaste/derp.crt` loaded automatically.