documentation update

docs/services/entity-extraction.md

@@ -99,7 +99,7 @@ returns without writing anything.
 
 For each entity in `parsed.entities`:
 
-1. Validate `name`, `type` (must be in `ENTITY_TYPES`), and not in `IGNORED_NAMES`
+1. Validate `name`, `type` (must be in `ENTITY_TYPES`), and not a greeting via `isIgnoredName(name)`
 2. Call `upsertEntity(name, type, notes)`:
    - **Insert**: creates new row with `mention_count = 1`, `source = 'extraction'`
    - **Conflict** on `(name, type)`: increments `mention_count`, updates `last_seen_at`, preserves existing `notes` if new extraction returns null
@@ -109,7 +109,27 @@ For each entity in `parsed.entities`:
 
 **Valid entity types:** `person`, `place`, `project`, `technology`, `concept`, `organization`
 
-**Stoplist (ignored names):** `good morning`, `good night`, `hello`, `goodbye`, `thanks`, `thank you`
+**Greeting filter:** `isIgnoredName(name)` normalizes the candidate before
+matching — lowercased, punctuation stripped (`/[^\w\s]/g`), trimmed — then
+tests membership against the `IGNORED_NAMES` set. Normalizing means variants
+like `"Good morning!"` or `" hello "` are caught, not just exact lowercase
+matches. Current set: `good morning`, `good night`, `good evening`,
+`good afternoon`, `hello`, `hi`, `hey`, `goodbye`, `bye`, `thanks`,
+`thank you`, `morning`.
+
+The extraction prompt also instructs the model not to emit greetings or
+conversational filler as entities, so the filter is a backstop rather than the
+sole defense — necessary because the model (qwen2.5:3b) will occasionally label
+a greeting as a `concept` or `topic`, both valid types that the `ENTITY_TYPES`
+check alone won't reject.
+
+> **Note:** the filter runs only at extraction time; it does not retroactively
+> remove greetings stored before the filter (or an entry) existed. Pre-filter
+> stragglers must be deleted manually via `DELETE /entities/:id`, which now
+> also removes the Qdrant vector (see `memory-service.md` → Delete Behaviour).
+> `\w` is ASCII-only, so non-ASCII greetings (e.g. `buenos días`) normalize
+> imperfectly — switch to `/[^\p{L}\p{N}\s]/gu` if the set gains non-ASCII
+> entries.
 
 ## Relationship Processing
 
@@ -137,4 +157,4 @@ All steps after the initial model call are wrapped in a single outer try/catch.
 If Ollama is unreachable, returns a non-200 status, or the JSON cannot be
 parsed, the function logs at `warn` level and returns. There is no retry logic.
 Individual entity embedding failures are caught per-entity and logged at `warn`
-level without affecting other entities in the same batch.
+level without affecting other entities in the same batch.