Refresh checkpoint with NIP-98 upload fix

CHECKPOINT-encryption.md

@@ -6,9 +6,9 @@ verified green at the moment this file was written.
 ## Where things are
 
 - Project: `/home/avi/Projects/skills/nost-feed-manager`
-- Git repo: `master` @ `3e3467b` ("Add compose preview with image attachments (NIP-92 imeta)"),
-  on top of `17e8ace` ("Clarify the Profiles subtitle about private keys") and `8eb6685`
-  ("Add reveal-secret-key after unlock (CLI + GUI)").
+- Git repo: `master` @ `03f6877` ("Sign NIP-98 auth for nostr.build image uploads"), on top of
+  `3e3467b` ("Add compose preview with image attachments (NIP-92 imeta)"), `17e8ace` (Profiles
+  subtitle copy), and `8eb6685` (reveal-secret-key).
 - The working tree is **clean** — everything from this session is committed.
 - `/home/avi/Projects/nostr_backend/nostr_backendmanager.md` (old-CLI docs) has been updated
   to match reality; it lives outside this repo so it is not part of any commit.
@@ -33,6 +33,14 @@ will appear (profile avatar + npub, the text, and any images), without publishin
 
 ## Commits this session (newest first)
 
+- `03f6877` "Sign NIP-98 auth for nostr.build image uploads" — fixes the attach-image flow, which
+  failed with "Unauthorized, please provide a valid nip-98 token". nostr.build now requires a
+  NIP-98 `Authorization` header. Backend: new `src/uploads.rs` (`nip98_authorization` signs a kind
+  27235 auth event with the active profile's key and returns `Nostr <base64>`), IPC method
+  `upload_auth { url, http_method }`, `nostr-sdk` feature `nip98` added. Electron:
+  `frontend/electron/main.ts` fetches the header from the backend and sends it on the upload.
+  Verified live: throwaway profile → IPC `upload_auth` → `curl` upload to nostr.build returned
+  `status: success` (temp data cleaned up).
 - `3e3467b` "Add compose preview with image attachments (NIP-92 imeta)" — 11 files, 1 new.
   Backend: `src/publish.rs` (`extract_image_urls`, `image_mime_from_url`, `image_tags` + tests).
   Electron: `frontend/electron/main.ts` (`pickImage`, `uploadImage`, routed from `backend:request`).
@@ -45,7 +53,7 @@ will appear (profile avatar + npub, the text, and any images), without publishin
 ## How it was verified (all green)
 
 ```
-cargo test            # 60 passed
+cargo test            # 64 passed
 cargo clippy --all-targets   # clean
 cargo fmt --check     # clean
 cargo build --release # builds (rebuilt so the GUI runs the new backend)
@@ -53,10 +61,13 @@ npm run typecheck     # clean (frontend/)
 npm run lint          # clean (pre-existing module warning only)
 npm run format:check  # clean
 npm test              # 60 passed (11 files)
-npm run build         # rebuilds the React bundle (dist/)
 npm run electron:build # compiles the Electron main process
 ```
 
+Plus a live upload test: created a throwaway profile under `XDG_DATA_HOME=/tmp/...`, got the
+`upload_auth` header through the IPC `serve` loop, and `curl`-uploaded a tiny PNG to nostr.build —
+returned `status: success`. Temp data cleaned up.
+
 ## How to resume
 
 1. Open the repo: `cd /home/avi/Projects/skills/nost-feed-manager`
@@ -72,6 +83,7 @@ npm run electron:build # compiles the Electron main process
 ## Outstanding / next steps (if you continue)
 
 - Nothing uncommitted. Possible follow-ups: a real feed view (currently Home only shows the last
-  publication); optional NIP-98 auth for nostr.build uploads; relay defaults in code still point at
-  `relay.damus.io` (503 upstream) and `relay.nostr.band` (timeout) — user's local settings already
-  use `nos.lol` + `relay.primal.net` instead.
+  publication); the upload uses the active profile's key for NIP-98 (so an encrypted, locked vault
+  needs unlocking before attaching an image — the attach error explains this); relay defaults in code
+  still point at `relay.damus.io` (503 upstream) and `relay.nostr.band` (timeout) — user's local
+  settings already use `nos.lol` + `relay.primal.net` instead.