Fix minimize script: keep bluetooth+wifi, update baseline doc

docs/baseline-footprint.md

@@ -97,11 +97,17 @@ fonts-* xfonts-*
 python3-pygame python3-tk
 ```
 
+### Systemd Services Kept (Bluetooth & WiFi stay on)
+
+| Service | Reason to Keep |
+|---------|----------------|
+| `bluetooth` | Wireless MIDI controllers, tuner apps |
+| `wpa_supplicant` | WiFi for web UI, SSH, preset downloads |
+
 ### Systemd Services Disabled
 
 | Service | Reason |
 |---------|--------|
-| `bluetooth` | No BT on pedal |
 | `avahi-daemon` | No mDNS needed |
 | `triggerhappy` | We handle GPIO ourselves |
 | `ModemManager` | No modem |
@@ -126,13 +132,6 @@ snd_usbmidi_lib
 snd_rawmidi
 snd_seq_device
 snd_hwdep
-# (HDA Intel is x86 only, but harmless to list)
-
-# Bluetooth
-bluetooth btusb btbcm
-
-# WiFi (wired-only mode)
-brcmfmac brcmutil
 
 # Unused input devices
 joydev uvcvideo videobuf2_v4l2
@@ -142,6 +141,8 @@ r8152          # Realtek USB NIC
 xhci_pci       # USB 3.0
 ```
 
+**NOT blacklisted:** Bluetooth (`bluetooth`, `btusb`, `btbcm`) and WiFi (`brcmfmac`, `brcmutil`) — kept for wireless MIDI and web UI.
+
 ## What We Keep
 
 ### Essential Packages

docs/os-minimization-plan.md

@@ -0,0 +1,32 @@
+## Problem
+Strip the DietPi install down to the minimum footprint for the pedal. Profile baseline resource usage, then remove unnecessary packages and services. Target < 60MB idle RAM and < 500MB disk.
+
+## File scope
+- `scripts/dietpi-postinstall.sh` — DietPi first-boot setup with minimal packages
+- `scripts/minimize.sh` — identify and remove unused packages, disable unnecessary systemd services
+- `scripts/build-minimal-image.sh` — take the stripped install and produce a flashable image
+- `docs/baseline-footprint.md` — before/after resource comparisons
+
+## Approach
+1. Install DietPi minimal (no desktop, no software options)
+2. Install only what's needed: JACK, Python, PyTorch, cmake, GPIO libs, I2C tools
+3. Run `systemd-analyze blame` to identify slow services
+4. Disable: avahi, triggerhappy, ModemManager, systemd-resolved if not needed
+5. **KEEP: bluetooth (for MIDI controllers, wireless tuner apps), wifi (for web UI, preset downloads)**
+6. Use `dpkg-query -Wf '${Installed-Size}\t${Package}\n' | sort -rn` to find biggest packages, remove non-essentials
+7. Strip kernel modules not needed (remove sound modules for hardware we don't have, etc.)
+8. Document the removal process so it's repeatable
+9. Build a minimal SD card image from the stripped install
+
+## Dependencies
+Blocks on: Audio system setup (t_9deaa72c) — need JACK working first for baselines
+
+## Acceptance Criteria
+- [ ] Baseline footprint documented (RAM + disk before/after)
+- [ ] All unnecessary systemd services disabled
+- [ ] Blutetooth and wifi preserved and functional
+- [ ] Unused kernel modules removed
+- [ ] No functionality lost — JACK, NAM, MIDI, GPIO, I2S all still work
+- [ ] < 60MB idle RAM, < 500MB disk
+- [ ] Repeatable minimize script committed to repo
+- [ ] Boot time < 15 seconds to pedal ready

scripts/minimize.sh

@@ -87,9 +87,7 @@ info "Step 1: Removing unnecessary packages..."
 
 # ── Packages we KNOW we don't need on a headless audio pedal ──────────────
 PACKAGES_TO_PURGE=(
-    # Bluetooth (no BT on a pedal)
-    bluez bluez-tools bluez-firmware pi-bluetooth
-    # Printing
+    # Printing (no USB printers on a pedal)
     cups cups-bsd cups-client cups-common cups-core-drivers cups-daemon cups-filters cups-ppdc cups-server-common
     # Avahi/mDNS (not needed for local audio)
     avahi-daemon avahi-autoipd avahi-utils
@@ -183,7 +181,6 @@ fi
 info "Step 2: Disabling unnecessary systemd services..."
 
 SERVICES_TO_DISABLE=(
-    bluetooth
     avahi-daemon
     triggerhappy
     ModemManager
@@ -239,14 +236,11 @@ blacklist snd_hda_intel
 blacklist snd_hda_codec
 blacklist snd_hda_core
 
-# Bluetooth
-blacklist bluetooth
-blacklist btusb
-blacklist btbcm
+# Bluetooth — KEPT (wireless MIDI controllers, tuner apps)
+# Do NOT blacklist bluetooth modules
 
-# WiFi (wired-only mode)
-blacklist brcmfmac
-blacklist brcmutil
+# WiFi — KEPT (web UI, SSH, preset downloads)
+# Do NOT blacklist wifi modules
 
 # Unused input devices
 blacklist joydev