docs(adr): 0002 projection model — sustained regime, categorical confidence; glossary terms for regime, habit change, scenario range, coverage

CONTEXT.md

@@ -43,3 +43,19 @@ _Avoid_: Counter reset handling, drive swap detection
 **Endurance baseline**:
 The write-endurance value a projection consumes: a verified rated-TBW override stored with provenance when one exists, otherwise a coarse implied baseline derived from vendor wear and labeled as such.
 _Avoid_: TBW value, failure threshold, max writes
+
+**Sustained regime**:
+The most recent stretch of the observation history over which the observed usage habit has been stable; the interval whose write rate the usage-adjusted theoretical lifespan consumes.
+_Avoid_: Current window, detection period
+
+**Habit change**:
+A sustained divergence between recent and earlier daily write rates that starts a new sustained regime.
+_Avoid_: Spike, anomaly
+
+**Scenario range**:
+The spread of lifespan projections computed from the 7-, 28-, and 90-day horizons of the observation history, shown in place of a statistical interval.
+_Avoid_: Confidence interval, error bar
+
+**Coverage**:
+The share of wall-clock seconds inside monitoring periods whose usage-habit classification is known rather than unknown.
+_Avoid_: Uptime, sample count