feat: add coverage option text chapter

CURRICULUM.md

@@ -68,6 +68,11 @@ Flag numbers identify the weak dimension(s): 1=Concept Focus, 2=Starter Calibrat
 |---|---|---|---|---|---|
 | `sv/wide-readmem` | Wide Four-State Memory Loading | ✅ | — | `sv/always-ff` | `$readmemh`, address ranges, and non-power-of-two four-state packed words |
 
+### Chapter: Coverage Option Text (October 2026)
+| Slug | Title | Status | Score | Prereqs | Teaches |
+|---|---|---|---|---|---|
+| `sv/coverage-option-text` | Coverage Option Text | ✅ | — | `sv/covergroup-basics` | default and procedural assignment of a covergroup instance's `option.comment` |
+
 ### Chapter: Introduction
 | Slug | Title | Status | Score | Prereqs | Teaches |
 |---|---|---|---|---|---|

artifacts/tutorial/SUMMARY.md

@@ -90,7 +90,7 @@ One commit per issue, each with the test that fails before it and passes after:
 
 ### Landed capability chapters
 
-Added seven one-lesson chapters for user-facing SystemVerilog capabilities
+Added eight one-lesson chapters for user-facing SystemVerilog capabilities
 landed in Mox between September 22 and October 1, 2026. The UDP chapter
 tracks landing tip `36b040f6190c`, and the virtual-provider chapter tracks
 `3bc88e77921e`; the pinned browser WASM remains unchanged.
@@ -104,6 +104,7 @@ tracks landing tip `36b040f6190c`, and the virtual-provider chapter tracks
 | `sv/sequential-udp-init` | §§29.3.2, 29.6, 29.7 | starter FAIL; solution PASS in interpreter and compile modes | starter both_fail; solution PASS; output equal | `artifacts/tutorial/capability-receipts/*sequential-udp-init*` |
 | `sv/virtual-provider-closure` | §§8.20, 8.22 | starter FAIL; solution PASS in interpreter and compile modes | starter both_fail; solution both_pass; output equal | `artifacts/tutorial/virtual-provider-closure/*` |
 | `sv/wide-readmem` | §§21.4, 21.4.1 | starter FAIL; solution PASS in interpreter and compile modes | starter both_fail; solution both_pass; output equal | `artifacts/tutorial/wide-readmem/*` |
+| `sv/coverage-option-text` | §19.7, Table 19-1 | starter FAIL; solution PASS in interpreter and compile modes | starter both_fail; solution both_pass; output equal | `artifacts/tutorial/coverage-option-text/*` |
 
 The capability receipt summaries are in
 `artifacts/tutorial/capability-receipts/{summary,final-summary}.tsv`.
@@ -113,7 +114,7 @@ receipt are recorded in
 
 ## Receipt coverage on origin/main
 
-The 80 registered lesson slugs are now accounted for by either the original
+The 84 registered lesson slugs are now accounted for by either the original
 generic receipts, a capability-specific bundle, or the missing-matrix bundle
 at `artifacts/tutorial/receipts/20261001-missing/`. That matrix records the
 18 previously uncovered slugs: native Mox passes for both RTL lessons and all
@@ -173,6 +174,20 @@ The focused browser run is 1/1 through the pinned interpreter-backed WASM
 fallback, not native AOT. Receipts and the Mox landing provenance are under
 `artifacts/tutorial/wide-readmem/`.
 
+### Coverage option text chapter
+
+`sv/coverage-option-text` teaches the empty default for a covergroup instance's
+`option.comment` and its procedural assignment under IEEE 1800-2023 §19.7 and
+Table 19-1. The starter deliberately rejects the empty default; the solution
+passes native interpreter and compile modes. Xcelium and Mox agree on the
+starter `both_fail` and solution `both_pass` receipts. The focused browser run
+is an explicit expected failure for the pinned WASM's unlinked coverage runtime
+host-allocation call and is interpreter-only until a WASM rebuild; native AOT is
+not claimed. The corrected refdiff receipts retain separate source hashes and
+cache keys even when `reference_cached` is true. Receipts and the b481 landing
+provenance are under
+`artifacts/tutorial/coverage-option-text/`.
+
 ## WASM rebuild (done locally, NOT published; release `mox-wasm` is unchanged)
 Built with emsdk 4.0.21 from Mox main `9c5418532b9` (and landing `ea0fcd2`): mox-verilog, mox-sim, mox-bmc and
 mox-lec. Mox has no wasm target for mox-run (GAPS TUT-WASM-MOXRUN), so two more commits went in:

artifacts/tutorial/content-census.md

@@ -20,7 +20,7 @@ tutorial's runnable coverage for the landed readmem behavior.
 
 ## New landed-capability chapters
 
-These nine short chapters correspond to the user-facing Mox capabilities present
+These ten short chapters correspond to the user-facing Mox capabilities present
 on the current `origin/main` by October 1, 2026. The compile-mode status page is
 listed separately below because it reports qualification status rather than
 teaching a new language capability. Every solution passes Mox in both
@@ -39,14 +39,14 @@ attempts decryption without a key.
 | `sv/clocking-sampler-retention` | `3b1760ff2030378cfde16ca319e2c1b806ab9d31`, `test/Tools/mox-sim/mq93-m2-clock-sampler.sv` | §§14.3, 14.13: default `1step` samples before the clock event; explicit `#0` samples in Observed and retains the sample through same-slot re-entry. | solution PASS; starter FAIL | solution PASS; starter FAIL | both PASS / both FAIL, output equal | added an explicit-`#0` sampler-retention exercise |
 | `sv/protected-envelope-boundary` | `c3799f427f1e51abcd389dcf15771150223cae75`, `test/Conversion/ImportVerilog/protected-comment-callback.sv` | §§34.2, 34.3, 34.4, 34.5.3–34.5.4: protected text is transformed before analysis and delimiters close the envelope; this lesson does not claim decryption. | solution PASS; starter FAIL | solution PASS; starter FAIL | `reference_only_fail` for solution; Xcelium attempts unkeyed decryption | added same-buffer opaque callback-boundary exercise |
 | `sv/wide-readmem` | `e7da9630dcd`, `test/Tools/mox-sim/aot-readmem-wide-fourstate.sv` | §§21.4, 21.4.1: `$readmemh` accepts optional address bounds and loads packed elements of an unpacked memory, preserving four-state digits. | solution PASS; starter FAIL | solution PASS; starter FAIL | starter `both_fail`; solution `both_pass`, output equal | added a width-calibration readmem exercise |
+| `sv/coverage-option-text` | `b481355f9fe`, `test/Tools/mox-sim/coverage-covergroup-option-comment-assignment.sv` | §19.7 and Table 19-1: an instance-specific covergroup `comment` defaults to `""` and may be assigned procedurally after instantiation. | solution PASS; starter FAIL | solution PASS; starter FAIL | starter `both_fail`; solution `both_pass`, output equal | added a default-and-assignment coverage-option exercise |
 
 The remaining current-main capability commits are queued for their own short
-chapters and are not silently folded into an existing lesson: coverage-option
-string preservation (`b481355f9fe`), VPI system-function argument marshalling
-(`d83c4b1dde8`), and interface-method `%m` receiver scope plus parenthesized
+chapters and are not silently folded into an existing lesson: VPI system-function
+argument marshalling (`d83c4b1dde8`), and interface-method `%m` receiver scope plus parenthesized
 virtual-interface receivers (`ed441eb5b58`).
 
-This census covers every lesson in `src/lessons/` (meta.js, 73 lessons) and CURRICULUM.md, checked against
+This census covers every lesson in `src/lessons/` (meta.js, 84 lessons) and CURRICULUM.md, checked against
 IEEE 1800-2023 (`spec/ieee-1800-2023.txt`) and IEEE 1800.2-2020 (UVM).
 
 Each row gives: lesson | claim/example | what is wrong | IEEE clause | evidence | proposed fix | severity.

artifacts/tutorial/coverage-option-text/README.md

@@ -0,0 +1,69 @@
+# Coverage option text receipt
+
+This receipt supports `sv/coverage-option-text`. The lesson teaches the
+instance-specific `option.comment` default and a procedural assignment on a
+covergroup instance. The starter deliberately rejects the standard empty
+default; the solution accepts it, assigns the runtime comment, samples one
+value, and prints `PASS`.
+
+## Standard and landing basis
+
+IEEE 1800-2023 §19.7 and Table 19-1 define instance-specific coverage
+options. The `comment` option defaults to `""`, is associated with the
+covergroup instance, and may be assigned procedurally after instantiation.
+The lesson does not claim that a simulator's coverage-report formatting is
+portable.
+
+The native capability landed in Mox commit `b481355f9fe`
+(`b481355f9fe63237a9a5f6307accb8a0133e1e77`), recorded by
+`/var/tmp/thomas-ahle/fleet/artifacts/landing/push-b481355f9fe.md`. The exact-
+tip qualification established the nine named Chapter-19 controls at 9/9.
+The native receipt uses `/var/tmp/thomas-ahle/wt/landing/build-dev-fast` at
+`35ec19ea7f9398d76cf704252703ae731dad04d5`, which contains b481 as an
+ancestor. No Mox worktree was modified.
+
+## Native runs
+
+The native runs use CPUs `0-79` and a 30-second wall guard. The logs use
+`mox-verilog` plus `mox-sim`; the build also has no `mox-run` binary.
+
+| variant | mode | exit | first result line |
+|---|---:|---:|---|
+| starter | interpret | 0 | `FAIL: starter rejected the empty default comment` |
+| starter | compile | 0 | `FAIL: starter rejected the empty default comment` |
+| solution | interpret | 0 | `PASS` |
+| solution | compile | 0 | `PASS` |
+
+Both compile logs report `AOT interpreter invocations total: 0`. The committed
+logs are the six `*-{import,interpret,compile}.log` files in this directory.
+
+## Differential runs
+
+`refdiff` was run on each committed fixture against the same native build:
+
+```text
+/var/tmp/thomas-ahle/fleet/bin/refdiff src/lessons/sv/coverage-option-text/coverage_option_text.sv --build-dir /var/tmp/thomas-ahle/wt/landing/build-dev-fast
+/var/tmp/thomas-ahle/fleet/bin/refdiff src/lessons/sv/coverage-option-text/coverage_option_text.sol.sv --build-dir /var/tmp/thomas-ahle/wt/landing/build-dev-fast
+```
+
+- `starter-refdiff.json`: `both_fail`; both engines reject the deliberate
+  wrong expectation of a nonempty default.
+- `solution-refdiff.json`: `both_pass`; normalized outputs are equivalent.
+- The committed refdiff JSON `sha256` field is the exact committed source
+  hash; `refdiff_cache_key` is the separate 64-hex receipt cache identity.
+  The receipts were regenerated from the committed fixtures with the commands
+  above. `starter-source.sha256` and `solution-source.sha256` independently
+  repeat the source binding. Both corrected receipts record
+  `reference_cached: true`; the cache key preserves provenance but does not
+  claim a fresh independent Xcelium run. Standing ruling — `general: refdiff
+  cache identity is receipt provenance, not a runtime performance cache`.
+
+## Browser qualification
+
+The browser result is recorded in `browser-qa.md`. It is an expected pinned-WASM
+failure caused by the unlinked coverage runtime host-allocation call
+`__mox_sim_register_host_allocation`; the explicit `test.fail` remains until a
+WASM rebuild. Native Mox passes. Browser qualification is interpreter-only
+until that linkage is rebuilt, and does not qualify native AOT. Standing ruling
+— `general: pinned interpreter fallback is an explicitly scoped browser
+compatibility path`.

artifacts/tutorial/coverage-option-text/browser-qa.md

@@ -0,0 +1,15 @@
+# Browser QA receipt
+
+Command:
+
+```text
+npx playwright test e2e/qa-all-lessons.spec.js --grep 'Coverage Option Text' --reporter=line
+```
+
+Result: `1 passed` as an expected failure (`e2e/qa-all-lessons.spec.js:67:5`,
+lesson `[32]`, `run`), wall time `33.6s`.
+
+The pinned browser WASM route fails with the known unlinked coverage runtime
+host-allocation call (`__mox_sim_register_host_allocation`); native Mox passes.
+The entry is an explicit `test.fail` for a WASM rebuild, not a tutorial-source
+failure and not native AOT qualification.