ckpool: expose bestever in runtime socket JSON

Upstream ckpool tracks user/worker best_ever across block solves but
only emits it in the on-disk users.json/workers.json persistence files,
not in the runtime socket API (userinfo() / workerinfo() in
stratifier.c). Consumers that poll the socket — like kamado-api — see
bestdiff reset to zero on every block solve via reset_bestshares()
with no all-time field to fall back on. That is the "best share stuck
at zero after a block" UX we want to fix in Kamado.

0001-expose-bestever-in-runtime-json.patch adds bestever to the two
JSON_CPACK calls so the UI can show current-round and all-time side
by side. No behavioral change, no impact on share validation or block
handling. Candidate for upstreaming.

Also surfaces BestEver in api/internal/ckpool types (User, Worker).
Gracefully degrades to 0 on an unpatched ckpool.

api/internal/ckpool/types.go

@@ -35,12 +35,15 @@ type PoolStats struct {
 	DSPS10080    float64 `json:"dsps10080"`
 }
 
-// User is one entry in the `users` response.
+// User is one entry in the `users` response. BestEver is exposed by the
+// Kamado ckpool patch (patches/0001-expose-bestever-in-runtime-json.patch)
+// and will be 0 against an unpatched upstream ckpool.
 type User struct {
 	User      string  `json:"user"`
 	ID        int64   `json:"id"`
 	Workers   int     `json:"workers"`
 	BestDiff  float64 `json:"bestdiff"`
+	BestEver  float64 `json:"bestever"`
 	DSPS1     float64 `json:"dsps1"`
 	DSPS5     float64 `json:"dsps5"`
 	DSPS60    float64 `json:"dsps60"`
@@ -53,7 +56,8 @@ type UsersResponse struct {
 	Users []User `json:"users"`
 }
 
-// Worker is one entry in the `workers` response.
+// Worker is one entry in the `workers` response. BestEver requires the
+// Kamado ckpool patch; see User above.
 type Worker struct {
 	User      string  `json:"user"`
 	Worker    string  `json:"worker"`
@@ -64,6 +68,7 @@ type Worker struct {
 	DSPS1440  float64 `json:"dsps1440"`
 	LastShare int64   `json:"lastshare"`
 	BestDiff  float64 `json:"bestdiff"`
+	BestEver  float64 `json:"bestever"`
 	MinDiff   float64 `json:"mindiff"`
 	Idle      bool    `json:"idle"`
 }

ckpool/patches/0001-expose-bestever-in-runtime-json.patch

@@ -0,0 +1,32 @@
+diff --git a/src/stratifier.c b/src/stratifier.c
+index 8281fa02..c94ca645 100644
+--- a/src/stratifier.c
++++ b/src/stratifier.c
+@@ -4007,9 +4007,10 @@ static json_t *userinfo(const user_instance_t *user)
+ {
+ 	json_t *val;
+ 
+-	JSON_CPACK(val, "{ss,si,si,sf,sf,sf,sf,sf,sf,si}",
++	JSON_CPACK(val, "{ss,si,si,sf,sf,sf,sf,sf,sf,sf,si}",
+ 		   "user", user->username, "id", user->id, "workers", user->workers,
+-	    "bestdiff", user->best_diff, "dsps1", user->dsps1, "dsps5", user->dsps5,
++	    "bestdiff", user->best_diff, "bestever", (double)user->best_ever,
++	    "dsps1", user->dsps1, "dsps5", user->dsps5,
+ 	    "dsps60", user->dsps60, "dsps1440", user->dsps1440, "dsps10080", user->dsps10080,
+ 	    "lastshare", user->last_share.tv_sec);
+ 	return val;
+@@ -4128,11 +4129,12 @@ static json_t *workerinfo(const user_instance_t *user, const worker_instance_t *
+ {
+ 	json_t *val;
+ 
+-	JSON_CPACK(val, "{ss,ss,si,sf,sf,sf,sf,si,sf,si,sb}",
++	JSON_CPACK(val, "{ss,ss,si,sf,sf,sf,sf,si,sf,sf,si,sb}",
+ 		   "user", user->username, "worker", worker->workername, "id", user->id,
+ 	    "dsps1", worker->dsps1, "dsps5", worker->dsps5, "dsps60", worker->dsps60,
+ 	    "dsps1440", worker->dsps1440, "lastshare", worker->last_share.tv_sec,
+-	    "bestdiff", worker->best_diff, "mindiff", worker->mindiff, "idle", worker->idle);
++	    "bestdiff", worker->best_diff, "bestever", (double)worker->best_ever,
++	    "mindiff", worker->mindiff, "idle", worker->idle);
+ 	return val;
+ }
+ 

ckpool/patches/README.md

@@ -9,8 +9,29 @@ Patches are applied in alphabetical order by filename. Use a numeric prefix to e
 
 ## Current state
 
-**No patches are applied.** The pinned upstream commit (`cfb0f83b`, tagged
+One Kamado patch is applied on top of the pinned upstream commit:
-as version 1.0) already includes every fix that Bassin issue #29 asked to
+
+| Patch                                         | What it does                                                                           |
+| --------------------------------------------- | -------------------------------------------------------------------------------------- |
+| `0001-expose-bestever-in-runtime-json.patch`  | Adds `bestever` field to the `users` / `workers` runtime socket JSON                   |
+
+### Why 0001 matters
+
+Upstream tracks `best_ever` internally in `user_instance_t` / `worker_instance_t`
+and zeroes `best_diff` on every block solve via `reset_bestshares()`. That
+is correct: `bestdiff` is "best share in the current round". But the runtime
+socket API (`userinfo()` / `workerinfo()` in `stratifier.c`) only emits
+`bestdiff`, so any consumer that talks to the socket — like `kamado-api` —
+sees the best share reset to 0 after every block and has no all-time field
+to fall back on. The on-disk `users.json` / `workers.json` persistence files
+do include `bestever`, but polling those is racy and lags the socket.
+
+This patch adds `bestever` to the runtime JSON so the UI can show both
+"this round" and "all-time" best share side by side. No behavioral change
+to share validation or block handling. Candidate for upstreaming.
+
+Beyond this patch, the pinned upstream commit (`cfb0f83b`, tagged as
+version 1.0) already includes every fix that Bassin issue #29 asked to
 backport, plus several improvements:
 
 | Upstream commit | What it fixes                                                  |