Add patch to rename coinbase branding from ckpool to kamado

Patch 0007 changes the 6-byte branding string in stratifier.c's
generate_coinbase() so mined blocks identify as "kamado" in the
coinbase scriptSig instead of "ckpool".

ckpool/patches/0007-rename-coinbase-tag-ckpool-to-kamado.patch

@@ -0,0 +1,13 @@
+diff --git a/src/stratifier.c b/src/stratifier.c
+index 8281fa02..38b2ac02 100644
+--- a/src/stratifier.c
++++ b/src/stratifier.c
+@@ -574,7 +574,7 @@ static void generate_coinbase(ckpool_t *ckp, workbase_t *wb)
+ 	len += wb->enonce2varlen;
+ 
+ 	wb->coinb2bin = ckzalloc(512);
+-	memcpy(wb->coinb2bin, "\x0a\x63\x6b\x70\x6f\x6f\x6c", 7);
++	memcpy(wb->coinb2bin, "\x0a\x6b\x61\x6d\x61\x64\x6f", 7);
+ 	wb->coinb2len = 7;
+ 	if (ckp->btcsig) {
+ 		int siglen = strlen(ckp->btcsig);

ckpool/patches/README.md

@@ -17,6 +17,7 @@ alphabetical order:
 | `0001-expose-bestever-in-runtime-json.patch`             | Adds `bestever` field to the `users` / `workers` runtime socket JSON                          |
 | `0002-enable-socket-api-responses.patch`                 | Always reply on the listener socket so kamado-api gets responses even with `btcsolo: true`    |
 | `0003-share-error-as-stratum-array.patch`                | Maps `share_err` to Stratum spec error codes; emits `[code, msg, null]` per Slush             |
+| `0007-rename-coinbase-tag-ckpool-to-kamado.patch`        | Replaces hardcoded "ckpool" branding in coinbase scriptSig with "kamado" (same 6 bytes)       |
 
 ### Why 0001 matters