The web UI stores sibling configs for one model file (distinct config_id, e.g. a
smaller-context variant), and the front already routes by alias (_route_key:
"two configs of the same model with distinct aliases can be assigned to
different engines"). But engine startup keyed every text-model config by path
(_model_id -> path), so a second same-path entry OVERWROTE the first —
BOTH aliases then resolved to the last-registered config (verified: lisa and
lisa-32k both got n_ctx=32768, silently changing the primary too).

Fix: in main.py text-model registration, key the PRIMARY config by path (stays
path-addressable) and each SIBLING (same path, already seen) by its ALIAS, so
the two configs are distinct and each alias resolves to its own n_ctx. A sibling
without an alias is skipped (can't be addressed). The GGUF loader already reads
the file from cfg['path'], so an alias-keyed sibling still loads the right file.
Verified: lisa->178000, lisa-32k->32768, same underlying .gguf.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Mw2KQiswmD69T45fTfjKwW