docs: answer the RAM question alongside disk

Measured on a running install rather than estimated. The README already
gave 4 GB and 32 GB; what was missing is why the gap is that wide, which
is the model rather than NOMAD, and whether it comes out of VRAM or
system RAM.

Asked for by @mk-pmb on #1271.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F8Mgg1vd2eKSs8StZiuyMV

README.md

@@ -77,7 +77,7 @@ At its core, however, NOMAD is still very lightweight. For a barebones installat
 
 #### Minimum Specs
 - Processor: 2 GHz dual-core processor or better
-- RAM: 4GB system memory
+- RAM: 4GB system memory (the whole stack without AI runs in under 1 GB)
 - Storage: At least 5 GB free disk space
 - OS: Debian-based (Ubuntu 26.04 LTS recommended)
 - Stable internet connection (required during install only)

admin/docs/faq.md

@@ -29,6 +29,24 @@ NOMAD is designed for capable hardware, especially if you want to use the AI fea
 
 **For detailed build recommendations at three price points ($150–$1,000+), see the [Hardware Guide](https://www.projectnomad.us/hardware).**
 
+### How much RAM do I need?
+
+**Without the AI Assistant, the whole stack sits under 1GB.** Measured on a running
+install: the Command Center 241MB, MySQL 444MB, Redis 9MB, Kiwix 101MB, and the
+knowledge base index 155MB. That is why 4GB is a real minimum rather than a
+defensive one.
+
+**The AI is the variable, and it is the model rather than NOMAD.** Ollama idles at
+roughly 1.2GB, and a model needs about its download size resident while it answers,
+so an 8B model at ~4.6GB wants about that much on top. **8GB is workable for a small
+model, 16GB is comfortable, and 32GB is the recommendation if you want to run larger
+ones.**
+
+Where that memory comes from depends on your hardware. With a discrete GPU the model
+loads into VRAM and never touches system RAM, so VRAM is the number that limits which
+models you can run. With an integrated GPU or no GPU at all, it comes out of system
+RAM, which is why a CPU-only box needs more of it.
+
 ### How much storage do I need?
 
 **To install NOMAD itself: about 5GB, so leave 10GB free.** That covers the