lightningd: add watchman.h declarations

diff --git a/lightningd/Makefile b/lightningd/Makefile
index 4fb5afbc..2d6950d3 100644
--- a/lightningd/Makefile
+++ b/lightningd/Makefile
@@ -4,6 +4,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/anchorspend.c		\
 	lightningd/bitcoind.c			\
 	lightningd/chaintopology.c		\
+	lightningd/watchman.c			\
 	lightningd/channel.c			\
 	lightningd/channel_control.c		\
 	lightningd/channel_gossip.c		\
diff --git a/lightningd/watchman.c b/lightningd/watchman.c
new file mode 100644
index 00000000..9a1ed50a
--- /dev/null
+++ b/lightningd/watchman.c
@@ -0,0 +1,5 @@
+#include "config.h"
+#include <lightningd/watchman.h>
+
+/* Definitions land in subsequent commits (storage skeleton, watchman_new,
+ * send_to_bwatch, ack handling, enqueue/replay). */
diff --git a/lightningd/watchman.h b/lightningd/watchman.h
new file mode 100644
index 00000000..c06671a7
--- /dev/null
+++ b/lightningd/watchman.h
@@ -0,0 +1,87 @@
+#ifndef LIGHTNING_LIGHTNINGD_WATCHMAN_H
+#define LIGHTNING_LIGHTNINGD_WATCHMAN_H
+
+#include "config.h"
+#include <bitcoin/tx.h>
+#include <ccan/tal/tal.h>
+
+struct lightningd;
+struct pending_op;
+
+/* lightningd's view of bwatch.  bwatch lives in a separate process and tells
+ * us about new/reverted blocks and watch hits via JSON-RPC; watchman tracks
+ * what we've already processed and queues outbound watch ops while bwatch is
+ * starting up. */
+struct watchman {
+	struct lightningd *ld;
+	u32 last_processed_height;
+	struct bitcoin_blkid last_processed_hash;
+	u32 bitcoind_blockcount;
+	struct pending_op **pending_ops;
+};
+
+/**
+ * watch_found_fn - Handler for watch_found notifications (tx-based watches)
+ * @ld: lightningd instance
+ * @suffix: the owner string after the prefix (e.g. "42" for wallet/p2wpkh/42,
+ *          or "100x1x0" for gossip/100x1x0); the handler is responsible for
+ *          parsing whatever identifier it stored in that suffix
+ * @tx: the transaction that matched
+ * @outnum: which output matched (for scriptpubkey watches) or input for outpoint watches
+ * @blockheight: the block height where tx was found
+ * @txindex: position of tx in block (0 = coinbase)
+ *
+ * Called when bwatch detects a watched item in a block.
+ */
+typedef void (*watch_found_fn)(struct lightningd *ld,
+			       const char *suffix,
+			       const struct bitcoin_tx *tx,
+			       size_t outnum,
+			       u32 blockheight,
+			       u32 txindex);
+
+typedef void (*watch_revert_fn)(struct lightningd *ld,
+				const char *suffix,
+				u32 blockheight);
+
+/**
+ * depth_found_fn - Handler for blockdepth watch notifications.
+ * @depth: new_height - confirm_height + 1 (always >= 1)
+ * @blockheight: current chain tip height
+ *
+ * Called once per new block.  When the confirming block is reorged away,
+ * watch_revert_fn is called instead.
+ */
+typedef void (*depth_found_fn)(struct lightningd *ld,
+			       const char *suffix,
+			       u32 depth,
+			       u32 blockheight);
+
+/**
+ * watchman_new - Create and initialize a new watchman instance
+ * @ctx: tal context to allocate from
+ * @ld: lightningd instance
+ *
+ * Returns a new watchman instance, loading pending operations from datastore.
+ */
+struct watchman *watchman_new(const tal_t *ctx, struct lightningd *ld);
+
+/**
+ * watchman_ack - Acknowledge a completed watch operation
+ * @ld: lightningd instance
+ * @op_id: the operation ID that was acknowledged
+ *
+ * Called when bwatch acknowledges a watch operation.
+ */
+void watchman_ack(struct lightningd *ld, const char *op_id);
+
+/**
+ * watchman_replay_pending - Replay all pending operations
+ * @ld: lightningd instance
+ *
+ * Resends all pending watch operations to bwatch.
+ * Call this when bwatch is ready (e.g., on startup).
+ */
+void watchman_replay_pending(struct lightningd *ld);
+
+#endif /* LIGHTNING_LIGHTNINGD_WATCHMAN_H */