pi: trim extensions to 10, drop 22 unused

Remove from settings + npm manifest + disk: pi-powerline, pi-bar,
pi-subagents, gentle-engram, pi-prompt-template-model, pi-simplify,
pi-add-dir, pi-slopchop, pi-btw, pi-interactive-shell, pi-terminal-theme,
@plannotator/pi-extension, @tmustier/pi-raw-paste, @tmustier/pi-usage-extension,
@victor-software-house/pi-curated-themes, ponytail, pi-caveman.
Also drop unregistered pi-token-speed, pi-web-access, statusline-pi,
@juanibiapina/pi-powerbar (dup of pi-powerline), context-mode.
Keep: pi-mcp-adapter, pi-intercom, pi-ask-user, @juanibiapina/pi-extension-settings,
@devkade/pi-plan, @tmustier/pi-ralph-wiggum, @danielmeneses/pi-llama-swap,
pi-llama-cpp-stats, firecrawl, autoresearch.

dot_pi/agent/settings.json.tmpl

@@ -1,6 +1,6 @@
 {
-  "defaultProvider": "miche.llama",
+  "defaultProvider": "byte.llama",
-  "defaultModel": "qwen38-27b-ciru-promptforge",
+  "defaultModel": "ornith-1.5-apex-i-quality",
   "defaultThinkingLevel": "high",
   "quietStartup": true,
   "lastChangelogVersion": "0.84.2",
@@ -10,33 +10,16 @@
   "header": true,
   "header-info": true,
   "packages": [
-    "npm:pi-powerline",
-    "npm:pi-bar",
-    "npm:@juanibiapina/pi-extension-settings",
     "npm:pi-mcp-adapter",
-    "https://github.com/firecrawl/pi-firecrawl",
-    "npm:pi-subagents",
     "npm:pi-intercom",
-    "npm:gentle-engram",
-    "npm:pi-prompt-template-model",
     "npm:pi-ask-user",
+    "npm:@juanibiapina/pi-extension-settings",
     "npm:@devkade/pi-plan",
-    "npm:pi-simplify",
-    "npm:pi-add-dir",
-    "npm:@plannotator/pi-extension",
-    "npm:pi-slopchop",
-    "npm:@tmustier/pi-usage-extension",
-    "npm:@tmustier/pi-raw-paste",
-    "npm:pi-btw",
-    "npm:pi-interactive-shell",
-    "git:github.com/davebcn87/pi-autoresearch",
     "npm:@tmustier/pi-ralph-wiggum",
-    "npm:@victor-software-house/pi-curated-themes",
-    "npm:pi-terminal-theme",
-    "git:github.com/DietrichGebert/ponytail",
-    "git:github.com/jonjonrankin/pi-caveman",
     "npm:@danielmeneses/pi-llama-swap",
-    "npm:pi-llama-cpp-stats"
+    "npm:pi-llama-cpp-stats",
+    "https://github.com/firecrawl/pi-firecrawl",
+    "git:github.com/davebcn87/pi-autoresearch"
   ],
   "enableInstallTelemetry": false,
   "subagents": {