docs(todo): add priority and tag scheme

Adds an explicit [#A]-[#D] legend at the top of todo.org defining what each
priority level means in practice. Type and effort tag conventions live
alongside, since task-audit enforces both. [#A] now requires a SCHEDULED or
DEADLINE date. A task that can't be dated isn't really [#A]. It belongs at
[#B].

Tags split two ways. Type tags (:feature:, :chore:, :spec:, :bug:) are
mandatory. Effort and autonomy tags (:quick:, :solo:) are optional and
orthogonal. Both can apply to the same task.

Seeds a Workflow State section in notes.org for the :LAST_AUDIT: marker
that open-tasks.org Next Mode reads to decide whether to offer a task-audit
run. The marker starts unset. The first task-audit run populates it.

2 files changed, 35 insertions, 0 deletions

diff --git a/.ai/notes.org b/.ai/notes.org
index 0c75bb1..3228009 100644
--- a/.ai/notes.org
+++ b/.ai/notes.org
@@ -73,3 +73,11 @@ When Craig says "remind me" about something:
 
 Format:
 - =[YYYY-MM-DD]= Description of what to remind Craig about
+
+* Workflow State
+
+Markers maintained by workflows to record when they last ran. Read by other workflows that gate their behavior on freshness.
+
+:LAST_AUDIT:    (unset — first =task-audit= run will populate)
+
+Format: one =:MARKER: YYYY-MM-DD= line per workflow. Workflows overwrite their own marker on completion.
diff --git a/todo.org b/todo.org
index 1642b1c..12bdd25 100644
--- a/todo.org
+++ b/todo.org
@@ -5,6 +5,33 @@
 Tracking TODOs for the rulesets repo that span more than one commit.
 Project-scoped (not the global =~/sync/org/roam/inbox.org= list).
 
+* Priority and Tag Scheme
+
+** Priority
+
+- =[#A]= *Urgent risk or current workflow blocker.* Credential exposure, data loss, destructive behavior, startup breakage, failing tests that block work, or a feature/refactor that unblocks a core daily workflow. =[#A]= requires a =SCHEDULED:= or =DEADLINE:= date — if it can't be dated, it isn't really =[#A]=.
+- =[#B]= *Important planned work.* Concrete bugs, high-leverage architecture cleanup, brittle load-order or test gaps, dependency failures, or feature work with clear design and expected near-term use.
+- =[#C]= *Useful but optional.* Low-risk cleanup, ergonomics, smoke tests, investigations with limited current impact, or feature work that would improve the setup but isn't yet a committed workflow.
+- =[#D]= *Someday or watchlist.* Speculative features, tiny polish, upstream tracking, optimizations without current pain, deferred ideas that shouldn't compete with active maintenance.
+
+The scheme is importance-driven with optional urgency lift. Priority signals "does this matter and when," not "how big" — effort lives in the tags.
+
+** Tags
+
+Every task carries one *type tag* from this set:
+
+- =:feature:= — adds new capability.
+- =:chore:= — meta or housekeeping (tooling, sync, version bump, mechanical cleanup).
+- =:spec:= — design document, brainstorm output, or research-backed proposal that precedes implementation.
+- =:bug:= — fix to incorrect behavior.
+
+Optional *effort and autonomy tags* — orthogonal to type, both can apply on the same task:
+
+- =:quick:= — likely to take ≤30 minutes from start through verification.
+- =:solo:= — Claude can complete the work end to end, including verification, without input from Craig.
+
+Tags are assigned and refreshed by =task-audit=; =task-review= keeps them honest in passing.
+
 * Rulesets Open Work
 
 ** TODO [#C] Check that memories are sync'd across machines via git