Handle flexible auth provider IDs in cache

docs/nostr-auth.md

@@ -9,7 +9,8 @@ updates can evolve it without breaking existing users.
 - `bitvid:profileCache:v1` – short-lived metadata cache for profile names and
   avatars. See `js/app.js` for TTL and eviction rules.
 - `bitvid:savedProfiles:v1` – persistent list of accounts the user authenticated
-  with in this browser.
+  with in this browser. The payload embeds a `version` field that is currently
+  `2`.
 
 Both keys live in the main origin scope. Clearing one should not affect the
 other.
@@ -20,14 +21,14 @@ other.
 
 ```json
 {
-  "version": 1,
+  "version": 2,
   "entries": [
     {
       "pubkey": "<hex-encoded pubkey>",
       "npub": "<bech32 npub, optional>",
       "name": "<cached display name>",
       "picture": "<cached avatar URL>",
-      "authType": "<auth strategy>"
+      "authType": "<auth strategy or null>"
     }
   ],
   "activePubkey": "<hex pubkey or null>"
@@ -46,17 +47,18 @@ Notes:
 - `activePubkey` tracks the last account that successfully authenticated in this
   browser. It may be `null` when the user logs out but keeps saved entries.
 
-### `authType` enum
+### `authType` handling
 
-`authType` describes how the profile authenticated:
+`authType` describes how the profile authenticated and is stored exactly as the
+provider reported it (after trimming whitespace). Bitvid does not attempt to
+normalise these strings, so future auth integrations can safely persist custom
+identifiers.
 
-- `"nip07"` – Browser extension flow (current default).
-- `"nsec"` – Reserved for future direct key import or signer integrations. New
-  auth strategies should pick a distinct string and document how migration works
-  alongside any recovery tooling.
-
-When the app reads stored entries it normalises unknown values back to
-`"nip07"` but keeps recognised alternatives intact.
+- Legacy payloads (version `1`) did not include the field, so the loader treats
+  those entries as `"nip07"` and rewrites the payload at version `2`.
+- Newer providers may surface alternative IDs (for example, Wallet Connect
+  flows). UI components use provider metadata when available and otherwise fall
+  back to a generic label so unknown identifiers do not break rendering.
 
 ## Migration notes