notes: color leaves the model, the wire and all three surfaces

Step 3 of M315, and the destructive half. Steps 1 and 2 stopped every read of
this field: a card is one neutral surface per theme, and the only coloured
thing on a board is a tag. What was left was a column written by a picker and
read by nothing.

Rule 22 — the old path comes out completely. No flag, no fallback, no
"override if set".

Server: the column, the `?color=` facet, the create/update/serialise paths,
the sync assignment, the front-matter line, and Keep's colour map. Alembic
0029 drops it and sweeps `"color"` out of stored saved-filter params — a view
that silently filtered on a field the app no longer has would return nothing
and never say why. That sweep is Python, not `params::jsonb - 'color'`,
because Postgres has no try-cast and one malformed blob would abort a
migration that is running over somebody's saved views.

`NOTE_COLORS` moves from `models/note.py` to `colors.py`. A palette defined on
the model that lost one is an invitation to put the column back; labels still
name a colour, so the vocabulary belongs where the normalizer already is.

Core: the field, the facet, the `NoteCreateInput`, and every read and write in
store/push/pull. Local schema v9 drops the column and does the same
saved-filter sweep, guarded on `json_valid` so a corrupt blob loses a key
rather than becoming NULL. The uniffi layer drops `NoteEdit::Color` and
`NoteDraft.color` with it.

Web: `ColorPicker.vue`, the per-card swatch popover and its stylesheet rule,
the FilterBar colour row, the facet in the query round-trip, and the colour
half of the editor's baseline-and-save. Android: the `ColorSheet`, the
`Picker.COLOR` case, the toolbar's swatch dot, `EditorAction.SetColor`.

## The protocol: v4, and the floor deliberately stays at 3

Checked against `compat.rs` and the push handler rather than trusting the
`#[serde(default)]` annotation, because the v2 precedent points the other way:
v2 dropped `kind` and `title` and DID raise both floors, on the rule that
dropping a field a client sends and expects back is breaking.

`color` fails the second half of that test. A v3 client reading a v4 note gets
`"default"` from its own serde default and draws the colour it derives
locally — the board it drew yesterday. A v3 client pushing `color` has the key
ignored, since `_assign_note_fields` reads its payload key by key and never
validates the shape. Neither direction errors and neither shows anything
wrong. `title` was the note's NAME; this is a field that no longer renders.

So `SYNC_PROTOCOL_VERSION` and `CLIENT_PROTOCOL_VERSION` go to 4, and both
floors stay at 3. `docs/sync.md` carries the reasoning and the per-version
history, and its push example is brought back in line — it still listed
`title`, `kind` and `items`, all gone before this.

Import stays tolerant: a pre-M315 export or a Keep takeout carrying `color:`
imports fine, the key simply read past. Old exports must still import.

#3041

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_notes.py

@@ -4,7 +4,8 @@ import pytest
 
 from thoughtsync.app import create_app
 from thoughtsync.common import coerce_bool, parse_dt
-from thoughtsync.models.note import NOTE_COLORS, Note
+from thoughtsync.colors import NOTE_COLORS
+from thoughtsync.models.note import Note
 from thoughtsync.notes.checklist import (
     append_item,
     parse_items,
@@ -76,16 +77,16 @@ def test_normalize_color():
 
 
 def test_palette_has_core_colors():
+    # A LABEL's vocabulary since M315 — a note has no colour to be one of these.
     for c in ("default", "red", "orange", "yellow", "green", "teal", "blue", "purple", "pink", "gray"):
         assert c in NOTE_COLORS
 
 
 def test_serialize_shape():
-    n = Note(body="b", color="blue", pinned=True, archived=False)
+    n = Note(body="b", pinned=True, archived=False)
     s = n.serialize()
     assert "title" not in s  # there is no title field any more (M13 step 3)
     assert s["body"] == "b"
-    assert s["color"] == "blue"
     assert s["pinned"] is True
     assert s["archived"] is False
     assert s["trashed"] is False
@@ -442,6 +443,8 @@ def test_keep_spec_list_note_keeps_its_text_too():
         "textContent": "for the weekend",
         "listContent": [{"text": "Milk", "isChecked": False}, {"text": "Eggs", "isChecked": True}],
         "labels": [{"name": "shopping"}],
+        # Keep's own colour, which the importer now reads past: there is nothing on a
+        # note for it to land on, and a spec carrying a key nobody applies is a lie.
         "color": "TEAL",
         "isPinned": True,
         "isArchived": False,
@@ -451,7 +454,7 @@ def test_keep_spec_list_note_keeps_its_text_too():
     }
     spec = _keep_spec(kn, "Takeout/Keep")
     assert spec["body"] == "for the weekend"
-    assert spec["color"] == "teal"
+    assert "color" not in spec
     assert spec["pinned"] is True
     assert spec["archived"] is False
     assert spec["trashed"] is False
@@ -460,16 +463,18 @@ def test_keep_spec_list_note_keeps_its_text_too():
     assert spec["created_at"].year == 2020
 
 
-def test_keep_spec_text_note_folds_annotation_urls_and_maps_color():
+def test_keep_spec_text_note_folds_annotation_urls_and_drops_color():
     kn = {
         "textContent": "Read this later",
         "annotations": [{"url": "https://example.com"}],
-        "color": "BROWN",  # no brown in our palette → nearest (orange)
+        "color": "BROWN",
         "attachments": [{"filePath": "img.jpg", "mimetype": "image/jpeg"}],
     }
     spec = _keep_spec(kn, "Takeout/Keep")
     assert "https://example.com" in spec["body"]
-    assert spec["color"] == "orange"
+    # BROWN used to map to the nearest hue we had. There is no hue to map TO now, so a
+    # Keep import brings across everything except the one thing this app stopped having.
+    assert "color" not in spec
     # attachment path is resolved relative to the note JSON's folder
     assert spec["attachments"] == [{"file": "Takeout/Keep/img.jpg", "mime": "image/jpeg"}]
 
@@ -478,6 +483,8 @@ def test_native_spec_roundtrip_fields():
     n = {
         "title": "T",
         "body": "b",
+        # An export taken before M315 still carries this. Reading past it rather than
+        # rejecting the file is the whole point — old exports must still import.
         "color": "blue",
         "pinned": True,
         "archived": False,
@@ -491,7 +498,7 @@ def test_native_spec_roundtrip_fields():
     # _create_imported_note folds it into the body rather than dropping it.
     assert spec["title"] == "T"
     assert spec["body"] == "b"
-    assert spec["color"] == "blue"
+    assert "color" not in spec
     assert spec["pinned"] is True
     assert spec["trashed"] is False  # exports only carry live notes
     assert spec["created_at"].year == 2026
@@ -642,7 +649,6 @@ def test_note_markdown_writes_a_checklist_once():
     note = Note(
         display_title="shopping",
         body="shopping\n\n- [ ] milk\n- [x] eggs",
-        color="default",
         pinned=False,
         archived=False,
     )

tests/test_saved_filters.py

@@ -12,13 +12,16 @@ def app():
 def test_clean_params_whitelists_facet_keys():
     raw = {
         "q": "hi",
+        # A facet until M315. It is junk now, and has to be dropped like any other —
+        # a stored view that still filtered on a field the app lost would return
+        # nothing and never say why.
         "color": "yellow",
         "label": ["a"],
         "has_reminder": True,
         "junk": 1,
         "__proto__": 2,
     }
-    assert clean_params(raw) == {"q": "hi", "color": "yellow", "label": ["a"], "has_reminder": True}
+    assert clean_params(raw) == {"q": "hi", "label": ["a"], "has_reminder": True}
     assert clean_params("nope") == {}
     assert clean_params(None) == {}