wiki: remove Obsidian-style hashtag tags from 12 articles

These #hashtag tag lines render as plain text on MkDocs. All articles
already have tags in YAML frontmatter, so the inline tags were redundant.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

03-opensource/alternatives/freshrss.md

@@ -83,7 +83,3 @@ The `CRON_MIN=*/15` environment variable runs feed fetching every 15 minutes ins
 - **Works forever** — RSS has been around since 1999 and isn't going anywhere
 
 ---
-
-## Tags
-
-#freshrss #rss #self-hosting #docker #linux #alternatives #privacy

03-opensource/alternatives/gitea.md

@@ -89,7 +89,3 @@ For public open source — GitHub is fine, the network effects are real. For pri
 - Works entirely over Tailscale — no public exposure required
 
 ---
-
-## Tags
-
-#gitea #git #self-hosting #docker #linux #alternatives #vcs

03-opensource/alternatives/searxng.md

@@ -82,7 +82,3 @@ DDG is better than Google for privacy, but it's still a centralized third-party
 - Can be kept entirely off the public internet (Tailscale-only)
 
 ---
-
-## Tags
-
-#searxng #search #privacy #self-hosting #docker #linux #alternatives