Move ~300 test functions from 21 catch-all files (handlers_core_test.go,
handlers_coverage*_test.go, *_coverage_test.go) into the *_test.go file
matching each handler's source file. This makes tests discoverable by
convention: tests for handlers_guild.go live in handlers_guild_test.go.
New files: handlers_guild_mission_test.go, sys_time_test.go.
No test logic changed — pure file reorganization.
mockGuildRepoForMail and mockGuildRepoOps each implemented different
subsets of the 68-method GuildRepo interface. Adding any new method
required updating both mocks. Merged into a single mockGuildRepo with
configurable struct fields for error injection and no-op defaults for
the rest.
Cover 5 more handler files with mock-based unit tests, bringing
package coverage from 43.7% to 47.7%. Extend mockGuildRepoOps with
alliance, cooking, adventure, treasure hunt, and hunt data methods.
