feat(db): permission_grants, permissions and commands given to one account or character

A new table, permission_grants (MySQL migration 96, SQLite 79), and the IPermissionGrants interface with MySQL, SQLite
and TestSQL implementations. A row grants (or with deny, takes away) a dashboard permission, a slash command, a
permission category or every command up to a GM level, for one account or one character, with an optional expiry, who
granted it and when, and a note. Rows are never deleted: removing one sets revoked_at/revoked_by, so the table is also
the history. Nothing reads it yet.

Check: both migrations run on a fresh and an existing database; DatabaseParityTests PermissionGrants passes against
MariaDB (DLU_TEST_MYSQL_HOST) and SQLite gives the same results.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dDatabase/GameDatabase/ITables/IPermissionGrants.h

@@ -0,0 +1,43 @@
+#ifndef __IPERMISSIONGRANTS__H__
+#define __IPERMISSIONGRANTS__H__
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+/**
+ * Permissions and slash commands granted to (or denied from) one account or one character, on top of what its GM level
+ * allows (PermissionGrants.h). Rows are never deleted: removing a grant sets revokedAt, so the rows are also the history.
+ */
+class IPermissionGrants {
+public:
+	struct Grant {
+		uint64_t id{};
+		std::string targetType;    // "account" or "character"
+		int64_t targetId{};        // the account's ID, or the character's charinfo ID
+		std::string kind;          // "permission", "command", "permission_group" or "command_group"
+		std::string name;          // the permission key, command name, permission category or GM level
+		bool deny{};
+		int64_t expiresAt{};       // 0: never
+		std::string note;
+		int64_t grantedAt{};
+		uint32_t grantedById{};    // the account that granted it
+		std::string grantedBy;
+		int64_t revokedAt{};       // 0: not removed
+		std::string revokedBy;
+	};
+
+	virtual uint64_t InsertPermissionGrant(const Grant& grant) = 0;
+	virtual std::optional<Grant> GetPermissionGrant(uint64_t id) = 0;
+	// Every grant of one target, removed and expired ones too, newest first
+	virtual std::vector<Grant> GetPermissionGrants(const std::string& targetType, int64_t targetId) = 0;
+	// The grants in force at `now` (not removed, not expired) of an account and, when characterId isn't 0, one character
+	virtual std::vector<Grant> GetActivePermissionGrants(uint32_t accountId, int64_t characterId, int64_t now) = 0;
+	// Every target's grants, newest first: only the ones in force at `now`, or all of them (the history)
+	virtual std::vector<Grant> GetRecentPermissionGrants(bool activeOnly, int64_t now, uint32_t limit) = 0;
+	// Whether it was in force until now (false: no such grant, or already removed)
+	virtual bool RevokePermissionGrant(uint64_t id, const std::string& revokedBy, int64_t time) = 0;
+};
+
+#endif  //!__IPERMISSIONGRANTS__H__