P3: assets' posted and scheduled depreciation, their bases, and the K-1 on the tax basis (defect 13, D-41)

Book value is cost less what the books posted; the schedule's figure is
apart. An asset's acquired date comes from its entry. Contributed
property keeps its section 723 carryover basis apart from its depreciable
basis (the lower of value and adjusted basis), with its 704(c) built-in
gain and method. The K-1 worksheet reports tax-basis capital (Form 1065
Item L) beside the book figures, leaving open what only the CPA knows.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

docs/testing.md

@@ -25,7 +25,7 @@ promise.
 | Differential: GnuCash | another implementation, adjudicated (3) | `tests/oracle_gnucash.rs`, `oracle/gnucash/` | `just oracle` | ~2 min | weekly |
 | Formal proofs | Kani (bounded) and Lean (unbounded) | `src/proofs.rs`, `verify/lean/` | `just prove` | ~15-20 min (bounded by `entry_flows_of_a_reversal_mirror`, ~14 min; all 29 harnesses ~43 min of CPU, run in parallel) | weekly |
 | Fuzzing | crash, hang, broken books (4); for `fuzz_store_replay` (validly chained journals with fuzz-chosen events): books that open must verify, and the viewer must accept exactly what the writer does | `fuzz/fuzz_targets/`, corpora in `fuzz/corpus/` | `just fuzz <target> <secs>` | 10 min each | weekly |
-| Miri | undefined behavior in our use of dependencies (4) | the core's unit, bridge, invariant tests | `just miri` | ~2 min | on demand |
+| Miri | undefined behavior in our use of dependencies (4) | the core's unit, bridge, invariant tests (the exhaustive calendar walk aside) | `just miri` | ~4 min | on demand |
 | Golden | `tests/golden/fixture_company.json` (5) | `invariants.rs` | `just check` | <1s | every change |
 | Benchmarks | a baseline (6) | `ledger-core/benches/books.rs`, `ledger-store/benches/store.rs` | `just bench` | ~2 min | none (no budget, by decision) |
 | Mutation | can the tests fail? | `ledger-core` (2026-10-13: 1,011 caught + 13 timeouts of 1,024 viable, 0 missed) | `just mutants` | ~3 h | weekly |
@@ -1554,6 +1554,92 @@ version's journal format (rules.md B-27). Mutation testing waits for P12
 `upgrade`, `book_line`, `upgraded_lines`, `upgrade_explained`,
 `ASKED_UPGRADES`). None run.
 
+## P3: asset basis and tax-basis capital (2026-10-20)
+
+Defect 13 (assets: posted vs scheduled, the in-service and acquired dates,
+the contributed property's bases) and D-41's K-1 worksheet on the tax
+basis. Mutation runs wait for P12 (D-33); none was run.
+
+- **Named regressions** (the brief's reproductions, anonymized):
+  `list_assets_book_value_is_what_the_books_carry` and
+  `a_reversed_run_is_not_posted` (`ledger-mcp/tests/spec_assets.rs`),
+  `an_asset_bought_before_it_is_in_service_is_on_the_register_from_acquisition`,
+  `personal_use_contribution_keeps_its_723_basis_apart_from_depreciable_basis`,
+  `built_in_gain_is_fixed_at_contribution_not_book_cost`
+  (`ledger-core/tests/spec_asset_basis.rs`, which replaces
+  `spec_tax_basis.rs`). Each is also a bookspec example
+  (`bookspec/examples/assets-*.toml`).
+- **ledger-core:** `spec_asset_basis.rs` (every `AssetBasis::check`
+  refusal and its replay pairs, the figure table for each rule, legacy
+  records giving the figures they gave, the four-contributed-devices
+  shape, the acquired date from the link and its refusals, the disposal
+  floor, `accumulated_posted` and its edges: a run dated after `as_of`, a
+  reversal dated after it, a reversal dated before its run, a reinstated
+  run, disposal on and after `as_of`, `check_depreciation_run` and
+  `record_depreciation_run`); `tax_capital.rs` (tax-basis capital per
+  member with a cash contribution, a contribution of property, a
+  distribution and a year of depreciation; next year's beginning; cash-only
+  books; property without a basis; property distributed; the roll-forward
+  and reconciliation over spans); `properties.rs`
+  `prop_basis_figures_laws` (5,000 cases); `kernel_bridge.rs`
+  `basis_figures_agree`; Kani `basis_figures_laws` (`src/proofs.rs`, 83
+  checks, its cover satisfied); `spec_asset_tags.rs` (the register's
+  posted and scheduled figures, runs recorded as a store records them).
+- **ledger-store:** `asset_tags.rs` (`asset.basis_set` journaled under the
+  feature `asset_basis` (new books declare it as they are created),
+  replayed, reloaded from the database and rebuilt, and in the viewer; a
+  line whose figures disagree with today's formula still replays; an
+  unknown rule or method is newer, a malformed figure corrupt; pre-P3
+  `asset.tax_basis_set` lines give the figures they gave; P2's v12
+  database left as it is while this version builds its v13 file, runs
+  keyed by entry (`a_p2_database_is_left_and_v13_built_from_the_journal`);
+  v9 and v10 databases under this version's name rebuilt). The old books
+  (`books_an_earlier_version_wrote_open_to_its_figures`) open to exactly
+  their figures.
+- **ledger-mcp:** `spec_assets.rs` (the aliases `purchase_date`,
+  `in_service`, `tax_basis_rule`, `contributor_basis` and the old rule
+  names, noted, and refused when they disagree; the acquired date from the
+  acquisition entry; a value at contribution required; every refusal
+  changing nothing; list_assets as of a date, disposed and not yet
+  acquired; the register export's columns and totals).
+- **ledger-package:** `package.rs`
+  `the_k1_worksheet_reports_tax_basis_capital` (the CSV line by line).
+- **bookspec:** the one loader (`ledger-core/tests/bookspec.rs`) runs the
+  assets' examples in the shared shape: `setup.assets` with `acquired_by`
+  and `basis`, a `[[changes]]` `correct_asset`, and the queries
+  `register_row`, `register_totals`, `asset_basis`, `k1_tax_basis` and
+  `k1_reconciliation` (keyed `"<member>.<line>"`, beside `k1`'s book
+  figures); refused: a register row before the asset was acquired
+  (`a_register_row_before_the_asset_was_acquired_is_refused`), an
+  `acquired_by` naming an event with no entry
+  (`an_asset_acquired_by_an_event_with_no_entry_is_refused`), a figure for
+  a tax line the books can't know (`a_tax_line_the_books_cant_know_is_open`)
+  and a member's reconciliation leaving a cause out
+  (`a_members_reconciliation_shows_every_cause`).
+- **ledger-import:** `asset_register.rs` (`pdf_shows_723_and_depreciable_basis`
+  and the other PDF checks) and `spec_import.rs` (XLSX columns, totals,
+  reconciliation and notes).
+- **ledger-gui:** `tests/assets.rs` (`basis_figures_are_ledger_cores`,
+  `journal_text_names_each_basis_figure`, the "Confirm its value" and
+  "Choose a §704(c) method" items); `pages/assets.rs`
+  (`an_assets_page_shows_its_own_book_value`: cost less posted, the
+  schedule beside it); `pages/reports.rs`
+  (`asset_register_report_carries_tax_basis`).
+
+**For P12 (mutation targets):** `kernel::basis_figures` (min for max, the
+sign of the gain, purchase to a contribution); `Ledger::accumulated_posted`
+and `assets::run_chain_entries` (`<=` for `<` on the entry and reversal
+dates, the disposed → 0 branch, the alternating sign); `live_depreciation_run`'s
+reversal test; `check_depreciation_run`'s arms; the register filter
+`acquired <= as_of` and `asset_acquired_date`'s min; `AssetBasis::check`,
+`check_journaled` and `check_legacy_journaled` arms; the acquisition and
+in-service date refusals; the disposal floor; the MCP `aliased` logic
+(both given and differing); `asset_basis_from_journal` (newer vs corrupt);
+the projection loader's two key sets; `tax_capital::share` and
+`entry_property` (the mismatch branch, the unknown sum), the open-item
+conditions (`in_service`, the disposal window), and the reconciliation's
+signs.
+
 ## Benchmarks (baseline 2026-10-13)
 
 No budget, by decision (the owner, 2026-10-13: the books do little work