[datlechin]

Summary

• Keep etcd keys, values and prefix range ends as bytes so reads, edits and deletes target the stored keys.
• Preserve non-UTF-8 keys, leading byte order marks, invisible characters and keys starting with -- through generated commands.
• Read command verbs literally and decode byte escapes only for key and value arguments, including when a newer plugin runs on an older app.
• Enforce the app's read-only and delete limits on every command execution path.
• Reject negative or overflowing page bounds in tagged range queries.
• Pair with docs(databases): describe etcd byte keys and quoting docs#175.

Test plan

• Byte-range and quote/parse regressions cover every byte, binary values, empty prefixes and Unicode edge characters.
• Parser regressions cover literal verbs, released-host command rules, command tiers and read-only/delete limits.
• Page-bound probe compiles the real driver parser and checks invalid bounds and valid boundary values.
• Update QueryClassifierNonSqlTests.etcdDestructiveSubcommands and etcdReadSubcommands for the deliberate bare-verb rule; etcdQuotedVerbs now checks the quoted cases stay unknown and cannot execute.
• After merging main, the app and etcd plugin build. All 286 selected tests pass: 212 hosted parser/classifier tests, 26 etcd core tests and 48 DuckDB core tests.
• Project generation, manifest lint and plugin linkage checks pass after the merge. The earlier 10-case page-bound probe, docs and localization checks pass. The all-plugin build still lacks the local Dameng archive.