🚧 WIP

docs/spec/software-spec.md

@@ -588,7 +588,8 @@ unchanged whether or not CSV streaming is used.
   deterministic tick (the engine or the runner advances the tick clock,
   never wall-clock arithmetic): **`state = env.observe()`** returns the
   state of ALL modules — DI/DO/AI/AO channels, engineering units, per-type
-  I/O codes, configured names, plus active aliases and parameters — →
+  I/O codes, configured names, analog display ranges (FR-10.2.14),
+  plus active aliases and parameters — →
   `env.model(state, dt)` (the caller-supplied plant physics) → **`apply()`
   writes the new field state**. The environment owns no policy; plant
   models are supplied by subclassing (FR-8.2.17).
@@ -602,15 +603,19 @@ unchanged whether or not CSV streaming is used.
   Exactly one decision source may own an alias per tick (ownership
   conflicts are validation errors, extending FR-8.2.2).
 - FR-8.2.16: **Environment API surface** (concrete):
-  `env.observe() -> PlantState` (all channels, aliases, parameters,
-  sim-time); `env.apply(values, force=False)` (keys: I/O code or alias
+  `env.observe() -> PlantState` (all channels with names and analog
+  display ranges, aliases, parameters, sim-time); `env.apply(values, force=False)` (keys: I/O code or alias
   name; DI/AI default, DO/AO require force; unknown keys are errors);
   `env.model(state, dt_s)` — override point for plant physics, returning
   new field values; `env.is_done(state) -> bool` — optional end
   criterion, default False (runs until manually stopped);
   `env.reset()` — deterministic fresh episode; `env.tick_ms` /
   `env.sim_time_ms` (read-only clock); `env.parameters` /
-  `env.invariants` attachments.
+  `env.invariants` attachments. `PlantState.channel(key)` returns
+  the full channel record by I/O code or by configured application
+  name (FR-10.2.11); `by_code()` returns values by I/O code;
+  `channel_range(key)` returns an analog channel's display range
+  (min, max) — always defined for AI/AO (dense store, FR-10.2.14).
 - FR-8.2.17: **Environment authoring & runners**: environments are easy
   to create and call — a subclass of `PlantEnv` overriding `model()`
   (and optionally `is_done()`) in any importable module
@@ -1056,6 +1061,14 @@ Terminal monitors (§9) suffice for single engineers, but FAT benches are
   onto the bar). Simulated AI values and AO forces accept negative
   numbers within the same window; values are stored in the image
   as their 16-bit two's-complement representation.
+  **Dense runtime store** (2026-10-04): `node.channel_ranges` is
+  always complete — every analog channel of the current layout has
+  an entry (unconfigured channels carry the materialized default),
+  codes that no longer match an analog channel are pruned on
+  rebuild, so envs and API consumers can read ranges without
+  default-fallback guesswork. Persistence (node YAML, config
+  export) stays **lean**: only explicit non-default entries are
+  written, so defaults survive a future DEFAULT_RANGE change.
 
 ### 10.3 Implementation decisions (binding, 2026-10-03)