forum trust circle: trust-gated content exchange via subscription graph

readme: document trust circle design

readme: tone down trust circle language to match existing style

remove forum_enabled toggle: subscribing IS trusting, no intermediate state

tinyweb_forum/db.py

@@ -105,6 +105,20 @@ class ForumDB:
             db.execute("ALTER TABLE synced_instances ADD COLUMN consecutive_failures INTEGER DEFAULT 0")
         except Exception:
             pass
+        db.execute(
+            "CREATE TABLE IF NOT EXISTS forum_trust_sources ("
+            "  instance_hash TEXT NOT NULL,"
+            "  source_hash TEXT NOT NULL,"
+            "  hops INTEGER NOT NULL,"
+            "  PRIMARY KEY (instance_hash, source_hash)"
+            ")"
+        )
+        db.execute(
+            "CREATE TABLE IF NOT EXISTS forum_trust ("
+            "  instance_hash TEXT PRIMARY KEY,"
+            "  min_hops INTEGER NOT NULL"
+            ")"
+        )
         db.commit()
         db.close()
 
@@ -676,6 +690,106 @@ class ForumDB:
         finally:
             self.return_db(db)
 
+    # --- Forum Trust ---
+
+    def add_trust_source(self, instance_hash, source_hash, hops):
+        db = self.get_db()
+        try:
+            db.execute(
+                "INSERT OR IGNORE INTO forum_trust_sources "
+                "(instance_hash, source_hash, hops) VALUES (?, ?, ?)",
+                (instance_hash, source_hash, hops),
+            )
+            existing = db.execute(
+                "SELECT hops FROM forum_trust_sources "
+                "WHERE instance_hash=? AND source_hash=?",
+                (instance_hash, source_hash),
+            ).fetchone()
+            if existing and hops < existing["hops"]:
+                db.execute(
+                    "UPDATE forum_trust_sources SET hops=? "
+                    "WHERE instance_hash=? AND source_hash=?",
+                    (hops, instance_hash, source_hash),
+                )
+            self._recompute_trust_view(db)
+            db.commit()
+        finally:
+            self.return_db(db)
+
+    def remove_trust_source(self, source_hash):
+        db = self.get_db()
+        try:
+            rows = db.execute(
+                "WITH RECURSIVE cascade(h) AS ("
+                "  VALUES(?)"
+                "  UNION ALL"
+                "  SELECT fts.instance_hash FROM forum_trust_sources fts"
+                "  INNER JOIN cascade c ON fts.source_hash = c.h"
+                ") SELECT h FROM cascade",
+                (source_hash,),
+            ).fetchall()
+            cascade_hashes = [r["h"] for r in rows]
+            placeholders = ",".join("?" for _ in cascade_hashes)
+            db.execute(
+                f"DELETE FROM forum_trust_sources WHERE source_hash IN ({placeholders})",
+                cascade_hashes,
+            )
+            self._recompute_trust_view(db)
+            db.commit()
+        finally:
+            self.return_db(db)
+
+    def remove_by_hash(self, instance_hash):
+        self.remove_trust_source(instance_hash)
+        db = self.get_db()
+        try:
+            db.execute(
+                "DELETE FROM forum_trust_sources WHERE instance_hash=?",
+                (instance_hash,),
+            )
+            self._recompute_trust_view(db)
+            db.commit()
+        finally:
+            self.return_db(db)
+
+    def is_trusted(self, instance_hash):
+        db = self.get_db()
+        try:
+            row = db.execute(
+                "SELECT 1 FROM forum_trust WHERE instance_hash=?", (instance_hash,)
+            ).fetchone()
+            return row is not None
+        finally:
+            self.return_db(db)
+
+    def get_trust_hops(self, instance_hash):
+        db = self.get_db()
+        try:
+            row = db.execute(
+                "SELECT min_hops FROM forum_trust WHERE instance_hash=?", (instance_hash,)
+            ).fetchone()
+            return row["min_hops"] if row else None
+        finally:
+            self.return_db(db)
+
+    def get_all_trusted_hashes(self):
+        db = self.get_db()
+        try:
+            return [
+                r["instance_hash"] for r in db.execute(
+                    "SELECT instance_hash FROM forum_trust"
+                ).fetchall()
+            ]
+        finally:
+            self.return_db(db)
+
+    def _recompute_trust_view(self, db):
+        db.execute("DELETE FROM forum_trust")
+        db.execute(
+            "INSERT INTO forum_trust (instance_hash, min_hops) "
+            "SELECT instance_hash, MIN(hops) FROM forum_trust_sources GROUP BY instance_hash"
+        )
+
     # --- Peer Liveness ---
 
     def record_sync_result(self, peer_hash, success):