T5.4 - CR-005: a per-project location taxonomy, stored as codes

CLAUDE.md lists CR-005 among the change requests that get "silently half-built if
you treat them as frontend-only". This is the server half and the wizard half
together: a new table, four routes, an Alembic revision, and step 11.

CODES, NOT DISPLAY STRINGS, because CR-018 rolls cost up by these values and a
rollup keyed on a label breaks the day somebody fixes a typo in it. Two columns
carry that: `code` is a node's own slug, derived once at import and never
recomputed; `path` is the full slug path, unique per project, and is what a work
package will store. Renaming a value changes `name` alone - the probe renames a
floor and demands its path comes back byte-identical, with its children's paths
intact.

DEACTIVATE, NEVER DELETE. There is no DELETE route, and the probe checks for its
absence (405) rather than trusting that nobody added one. Deactivating hides a
value from new work packages and cascades DOWN, because a floor nobody can pick
must not keep offering its sectors. Reactivating walks UP only - a sector may
have been switched off for its own reasons, and silently resurrecting it would
undo a decision nobody made twice. That asymmetry is deliberate and is pinned by
a named check so it does not get "fixed" into a surprise.

Import reports rather than merges. Rejected rows come back with the SOURCE line
number and a reason; duplicates are listed as duplicates, separated into "already
in this project" and "already on line N of this import". Reusing a parent is not
a duplicate - B1/L2/1P and B1/L2/2P share a building and a floor by design, and
only the full path repeating counts. Re-importing a deactivated value brings the
same row back rather than creating a second one; the probe checks the id.

One parser, on the server. A CSV is read in the browser and posted as text
exactly as a paste is, so "what does a blank column mean" has one answer.
Comma, semicolon and tab all work - a paste out of a spreadsheet is tab
separated and a saved CSV is not, and which one somebody has is a question the
machine can answer.

No guessed floor names. IMPLEMENTATION.md section 8 says the B100 list has not
been supplied. The seeded sample has "Sample" inside every string, and the probe
greps html/ and server/ for a location-shaped assignment containing any of the
review's real names.

  server/models.py                    LocationNode
  server/alembic/versions/e2a4c7d91b30_location_taxonomy.py
  server/app.py                       GET/POST/PATCH + import, parser, slug
  html/work-package-suite.html        step 11, an 11th rail button
  html/work-package-suite-app.js      the step's logic; LAST_STEP replaces 10
  html/work-package-suite-styles.css  the list, the report
  html/theme-light.css                .field-error, now declared once
  tests/locations_check.py            new - 58 checks
  tests/stepper_check.py              STEP_COUNT 10 -> 11

Done when
  [x] CSV upload and paste both work and report rejected rows with reasons
  [x] duplicates are detected and reported rather than silently merged
  [x] values are editable after import - rename, add, deactivate
  [x] deactivating hides it from new work packages; an existing package
      referencing it still resolves, because the row is retained
  [x] values are stored as codes suitable for grouping
  [x] no guessed real-world floor names exist anywhere in the code

Two decisions worth disagreeing with

  Step 11, appended, not step 2, inserted. Locations belong beside Project by
  subject. Renumbering 2-10 would touch every sop-step-N id, every
  collectStepData case, every gate key and the analytics history - a large
  silent-mismatch surface for an ordering change. The count now lives in one
  place (LAST_STEP), so reordering later is cheap.

  Any project member may edit the list, not only a Project Admin. It matches how
  the SOP baseline itself is authored: the Project Admin gate is on CHANGING a
  completed SOP, not on writing one. If the location list should be tighter than
  the SOP it belongs to, that is a product call.

Verified one at a time
  locations_check  58/58  new
  stepper_check    70/70  (11 steps)
  browser_check    71/71
  a11y             22/22  sop now rings 38 focusable elements
  url_state        23/23
  autosave         34/34
  aggregates       16/16
  pipeline         43/43
  launcher         58/58
  f_items          F1-F5 FIXED, F6 REPRODUCES (T7.2)
  alembic          upgrade / downgrade / upgrade all clean on a throwaway SQLite
                   file, and the migrated schema matches Base.metadata.create_all
                   column for column - dev auto-creates and production migrates,
                   so a divergence between the two is invisible until it ships

.field-error was declared in two page sheets by the end of T5.2 and would have
been three by T5.8, so it moved to theme-light.css. No colour literal added
anywhere: still 0 across all page sheets and inline blocks.

Question for the PR, per CLAUDE.md: the levels are fixed at building / floor /
sector. Micron's floors behave like buildings, which this handles by letting a
project use whichever levels it needs - but a job that wants a fourth level, or
different names for the three, cannot say so. Whether that is worth a
per-project level vocabulary is a product question; the schema would take it
without a migration.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

server/models.py

@@ -224,6 +224,68 @@ class ProjectMember(Base):
     created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
 
 
+class LocationNode(Base):
+    """One value in a project's Building / Floor / Sector taxonomy — CR-005.
+
+    The taxonomy differs per project. On Micron, floors within B100 behave like
+    separate buildings, so floor and sector are the unit of both execution and
+    cost tracking; on another job "building" may be the only level that means
+    anything. So it is configured once per SOP rather than hard-coded, and no
+    real-world floor name appears anywhere in this repository.
+
+    CODES, NOT DISPLAY STRINGS. `CR-018` rolls cost up by these, and a rollup
+    keyed on a label breaks the day somebody fixes a typo in it. Two columns
+    carry that:
+
+      code   this node's own slug among its siblings, derived once from the name
+             it was imported with and then NEVER recomputed — renaming a node is
+             a display change, which is exactly what makes rename safe for the
+             work packages already pointing at it.
+      path   the full slug path from the root, '/'-joined and unique per project
+             (`B100/L2/1P`). This is the grouping key and the value a work
+             package stores.
+
+    DEACTIVATE, NEVER DELETE. `active=False` hides a value from new work
+    packages; every existing package referencing it still resolves its label,
+    because the row is still there. Same rule as `CR-002`/`CR-016`: removal is
+    expressed as a toggle, and the data is retained.
+    """
+    __tablename__ = "location_nodes"
+    __table_args__ = (
+        UniqueConstraint("project_id", "path", name="uq_location_path"),
+    )
+
+    LEVELS = ("building", "floor", "sector")
+
+    id: Mapped[str] = mapped_column(String(40), primary_key=True)
+    project_id: Mapped[str] = mapped_column(
+        String(40), ForeignKey("projects.id", ondelete="CASCADE"), index=True
+    )
+    # Self-reference by id. No ForeignKey to its own table for the same reason the
+    # rest of this file declares none — see the module docstring — and because a
+    # self-referential FK plus SQLite's deferred-constraint behaviour makes a bulk
+    # import fiddly for no gain. Orphans are prevented in the API, which is the
+    # only writer.
+    parent_id: Mapped[Optional[str]] = mapped_column(String(40), nullable=True, index=True)
+    level: Mapped[str] = mapped_column(String(20), default="building")  # building | floor | sector
+    code: Mapped[str] = mapped_column(String(60), default="")           # own slug
+    path: Mapped[str] = mapped_column(String(200), default="", index=True)  # full slug path
+    name: Mapped[str] = mapped_column(String(200), default="")          # display label
+    active: Mapped[bool] = mapped_column(Boolean, default=True)
+    sort: Mapped[int] = mapped_column(Integer, default=0)
+    created_by: Mapped[str] = mapped_column(String(200), default="")
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow)
+    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow)
+
+    def to_dict(self) -> dict:
+        return {
+            "id": self.id, "project_id": self.project_id, "parent_id": self.parent_id,
+            "level": self.level, "code": self.code, "path": self.path, "name": self.name,
+            "active": bool(self.active), "sort": self.sort,
+            "created_at": _iso(self.created_at), "updated_at": _iso(self.updated_at),
+        }
+
+
 class Comment(Base):
     __tablename__ = "comments"