Add #rss command family with LLM tags and summaries (v0.20.0)

#rss subcommands on the command channel: help / add <url> <name> /
remove <name> / tags / sources / get <name|#tag>. Sources are stored in
a new rss_sources table in the existing MESH_DB_PATH file (second
node:sqlite connection, case-insensitive names); feeds parsed with
fast-xml-parser (RSS 2.0 + Atom); AI tags and headline summaries via
injected LlmService.chat() with bounded maxTokens (50/200).

CommandService gains prefix registration so one handler owns the whole
#rss family while #ping stays an exact match; wired in CommandModule's
factory — still no constructor-level cycle, no forwardRef. One dead feed
does not sink a tag summary.

src/commands/command.module.ts

@@ -1,20 +1,22 @@
 import { Module } from '@nestjs/common';
 import { MeshModule } from '../mesh/mesh.module.js';
 import { MeshService } from '../mesh/mesh.service.js';
+import { RssModule } from '../rss/rss.module.js';
+import { RssService } from '../rss/rss.service.js';
 import { CommandService } from './command.service.js';
 
 @Module({
-  imports: [MeshModule], // one-way only — the reverse edge is wired in the factory below, not via DI
+  imports: [MeshModule, RssModule], // one-way only — the MeshService reverse edge is wired in the factory below, not via DI
   providers: [
     {
       provide: CommandService,
-      useFactory: (mesh: MeshService) => {
-        const commands = new CommandService(mesh);
+      useFactory: (mesh: MeshService, rss: RssService) => {
+        const commands = new CommandService(mesh, rss);
         // break the cycle: MeshService can't inject us (its own factory would deadlock on this edge), so attach ourselves once we exist — mesh is guaranteed created here because it's our injected dependency
         mesh.attachCommands(commands);
         return commands;
       },
-      inject: [MeshService],
+      inject: [MeshService, RssService],
     },
   ],
   exports: [CommandService],