A junior month with one session has an unknown expected fee. When such
a month had a payment, the Go tooltip printed "Expected: 0" where
Python prints "Expected: ?", which made make parity fail on
/api/juniors.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The Go server now runs sync -> infer -> flush-cache by itself at the
times in SYNC_SCHEDULE (comma-separated HH:MM, default 04:00, "off"
disables), read in SYNC_TZ (default Europe/Prague). Nothing runs at
startup; an invalid value stops the server with an error.
- internal/scheduler: time-of-day parsing, Next, and the run loop
- banksync.Runner: one lock shared by /sync-bank and the scheduler so
runs never overlap, plus the status of the last run
- footer shows the last sync since start and the next scheduled run
- binary embeds time/tzdata because the Alpine image has no zone data
Deliberately not implemented in the legacy Python app, which is being
phased out; recorded in CLAUDE.md under "Deliberately Go-only features".
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
/sync-bank now uses one shared default window in both implementations:
1 November of the previous year to 31 December of the current year.
Payments dated around New Year are picked up in January; duplicates
are still filtered by Sync ID.
Python used a hardcoded 2026 window and would have stopped syncing on
2027-01-01; Go used the current calendar year only.
Adds make sync-year [YEAR=N] with the same window. The CLI default
without flags (last 30 days) is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- Default adult monthly rate 700 -> 600 CZK
- 2026-07 and 2026-08 set to 0; 2026-09 through 2026-12 added at 600
- Single-session fee is capped at the month's rate, so a 0-rate month
is free for one session as well
- Mirrored in Go and legacy Python; new calculate_fee parity fixtures
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Go stringified sheet cells with fmt.Sprint, so a numeric VS read with
UNFORMATTED_VALUE was rendered as 2.609767878e+09. Text columns of the
payments sheet now go through sheets.CellString, which never uses
exponent form; bank inference uses the same helper.
Both sync implementations now append VS as a text cell so Sheets keeps
it a string and leading zeros survive. Existing rows are not rewritten.
Python already read VS as a digit string; a regression test pins that.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Go (go/) becomes the primary implementation. The original Python
version moves to legacy/ and is kept runnable; new features are still
built in both (see the Dual implementation rule in CLAUDE.md).
- git mv app.py, scripts/, templates/, tests/, pyproject.toml, uv.lock
and build/ into legacy/
- Makefile: Python targets point at legacy/, venv in legacy/.venv,
CREDENTIALS_PATH exported for the root .secret/ file
- CI and make image build the Python image with legacy/ as context;
the Makefile is no longer copied into the image
- legacy/.dockerignore moved to the context root so it takes effect
- CLAUDE.md, docs/README.md, Go comments, fixture README, capture
script and VS Code launch config updated to the new layout
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Configured-month cases now read expected values from AdultFeeMonthlyRate /
JuniorFeeMonthlyRate via a mustRate helper that panics if a test month is
removed from the map. Fallback cases use AdultFeeDefault / JuniorFeeDefault.
This way the tests verify dispatch logic (0/1/2+ branching, map vs. fallback)
without breaking when rates are intentionally updated in the map.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Instead of hiding older months entirely, show all months in the from/to
selectors but default the from-select to the last MONTHS_TO_SHOW months
on page load. The "All" button resets to full history as before.
Python: passes months_to_show to render_template, IIFE sets fromSelect.value.
Go: adds MonthsToShow to response structs, data-months-to-show attr in
templates, filters.js reads it and defaults fromSelect after hideFutureMonths.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Show only the last MONTHS_TO_SHOW months (default 5) in the fee table columns
so the page fits on screen without horizontal scrolling. Reconciliation still
runs over the full month history so balances, credits, and debts are unaffected.
Set MONTHS_TO_SHOW=0 to show all months. Implemented in both Python and Go.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- 2026-05: 700 → 450 CZK
- 2026-06, 07, 08: 600 CZK (new months)
Changes are mirrored in both Python (scripts/attendance.py) and Go (go/internal/domain/fees/fees.go).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Add second Fio account (CZ0820100000002502035405 / 2502035405/2010).
Both accounts are fetched on every sync run and combined before dedup,
so the payments sheet accumulates transactions from either account.
QR codes now default to the new account.
Go:
- config.go: hardcoded Accounts/LoadedAccount slice replaces scalar
BankAccount + FioAPIToken; Config.BankAccount renamed QRAccount;
per-account tokens via FIO_API_TOKEN_NEW / FIO_API_TOKEN_OLD
- banksync.SyncToSheets: accepts []fio.Client, loops to combine txns
- cmd/fuj/main.go: buildFioClients helper; both sync call sites updated
- html_handler + build_adults/juniors: use Config.QRAccount
- New TestSyncToSheets_MultiAccount covers cross-account dedup
Python:
- config.py: ACCOUNTS list + LOADED_ACCOUNTS (tokens from env)
- fio_utils.py: fetch_transactions_for (per-account) +
fetch_transactions_all (loops all accounts)
- sync_fio_to_sheets.py: uses fetch_transactions_all
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Replace proportional split with a fill-first loop that allocates
min(remaining, deficit) to each matched month in user-supplied order,
where deficit = expected - already_paid. Prior transactions' contributions
are now properly accounted for, so a second payment on overlapping months
fills only what's still owed instead of splitting proportionally by total
expected. Surplus after all deficits are covered goes to the credit bucket.
Fixes: Matyáš Thér 200+550 showing 566/183 instead of 500/250.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Add TestEmbedCompleteness and TestStaticAssetsServed in
go/internal/web/assets_test.go. The completeness guard walks the
on-disk templates/ and static/ directories and asserts every file is
present in the corresponding embed.FS, catching forgotten files on
future additions. The static mux test hits /static/css/app.css and all
JS files through the same http.FileServerFS wiring used in server.go,
confirming assets are served from the embedded FS with correct
Content-Type and a 404 for unknown paths.
Standalone binary smoke test passed manually: binary copied to /tmp
(no adjacent templates/ or static/), assets served correctly.
Closes M6.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Replace bare <a href=/qr> Pay buttons with <button data-*> elements that
open an in-page #qrModal (matching Python's showPayQR UX), driven by a
new payment-qr.js vanilla-JS IIFE module. Remove the now-dead qrHref /
qrHrefAll template helpers from render.go.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds static/js/member-detail.js: fetches /api/<page> once on page load,
caches the response, and renders a per-member detail modal on [i] row click.
Keyboard nav: Esc closes, ↑/↓ walk visible (filtered) rows. All modal CSS
was already in place from M6.1.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Extract AssemblePayments(ctx) from ServePayments in api/handler.go,
mirroring the AssembleAdults/AssembleJuniors pattern
- Add PaymentsPageData view-model wrapper in render.go
- Rewire html_handler.go ServePayments to call AssemblePayments and
render with PaymentsPageData
- Replace payments.tmpl placeholder with real grouped-by-person ledger:
alphabetical member blocks, txn-table (Date/Amount/Purpose/Message),
newest-first rows, Unmatched/Unknown bucket
- Append ledger CSS classes to app.css (.ledger-container, .member-block,
.txn-table, .txn-date/amount/purpose/message, tr:hover)
- Add TestPaymentsPage markup test
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Extract AssembleJuniors(ctx) from ServeJuniors JSON handler so HTML
and JSON share the same view-model path (mirrors AssembleAdults pattern)
- Add JuniorsPageData wrapper in render.go
- Wire HTMLHandler.ServeJuniors to AssembleJuniors + render template
- Replace 4-line placeholder juniors.tmpl with full template:
member table, name filter, month-range filter, totals row,
Credits + Debts sections, Pay / Pay All buttons via /qr links
(no Unmatched section — matches Python juniors.html parity)
- J/A attendance breakdown ("3/500 CZK (4:2J,1A)") and "?" sentinel
rendered via MonthCell.Text from buildJuniorMemberRow, no extra
template logic needed
- All tests pass; make parity reports 3/3 routes OK
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two regressions made older periods invisible on the adults dashboard:
- 1257f0d (Mar 9) commented out ADULT_MERGED_MONTHS, removing the
Sep+Oct 2025 merged label. Restored only the 2025-09 → 2025-10
mapping (Dec and Jan are billed separately for adults; the
Dec → Jan mapping stays disabled per product decision). Mirrored
on the Go side. Test fixtures in sources_test.go now assert Sep
dates land in merged 2025-10 instead of 2025-09.
- 7774301 (Apr 9) added a JS onload default that set the From
selector to maxMonthIdx − 4 and immediately filtered the table,
hiding everything older than 5 months on first load. Dropped that
default in templates/adults.html and templates/juniors.html so
the From-selector starts at the oldest available month. Future
months are still removed from the dropdowns and hidden in the
table — only the past-month truncation is gone.
Note: the live adults attendance sheet had also been pruned to
start at 02.12.2025; restoring Sep/Oct/Nov 2025 columns from
Sheets version history is required to actually see those periods.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Map unpaid|partial → cell-unpaid (or cell-unpaid-current for current
month) and surplus → cell-overridden, matching Python's Jinja logic;
avoids emitting non-existent cell-partial/cell-surplus classes that
caused Pay buttons to escape the table.
- Add text-decoration: none to .pay-btn so anchor-based Pay links don't
show the default underline.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The lifted CSS defines .table-container with border: 1px solid #333 and
max-width: 1200px — without the wrapper the table stretched to full
viewport width and showed no border. Mirrors templates/adults.html.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Extract AssembleAdults(ctx) from ServeAdults so HTML and JSON API share one reconcile path.
- HTMLHandler gains *api.Handler; ServeAdults loads real data and renders adults.tmpl.
- AdultsPageData view model + qrHref/qrHrefAll funcMap (URL-encode /qr params, YYYY-MM→MM/YYYY).
- adults.tmpl: full reconcile table, per-cell status classes + cell-unpaid-current, Pay button hrefs,
totals row, credits/debts/unmatched sections, filter controls, sheet links.
- static/js/filters.js: NFD-normalize name filter + month-range column hiding; future months hidden by default.
- TestAdultsPage asserts member name and cell text against fixture data.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stand up the Go-native HTML frontend foundation:
- base.tmpl layout + nav/footer partials (three-tier nav, active-link highlighting)
- terminal-green-on-black theme extracted to static/css/app.css (served via embed.FS)
- HTMLHandler with stub pages for all five routes; / redirects to /adults
- NewRenderer parses per-page template sets at startup so parse failures abort boot
- Smoke test: each route returns 200 text/html with exactly one class="active" link
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
parseDates was using "02.01.2006" / "01/02/2006" which require
zero-padded fields. The Czech attendance sheet headers contain dates
like "1.6.2026", "23.3.2026", "6.4.2026" — Go silently dropped those
columns while Python's strptime accepted them. Effect was a missing
2026-06 month on /api/juniors plus undercounted attendance in any month
with single-digit columns; surfaced via make parity.
Use the unpadded reference forms "2.1.2006" / "1/2/2006" instead — Go's
time.Parse accepts both padded and unpadded inputs against them.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
/api/version returns each binary's own tag/commit/build_date, which
differs by design between independently built backends. Diffing it
always produces a false positive. Drop it from allRoutes; the route
remains reachable via `make parity ARGS="-route /api/version"`.
Also remove the vestigial `build_meta` allowlist entry (Python returns
the build dict as the top-level response body, not nested under
build_meta, so the scrubber never matched anything).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The transaction-row parser in services/membership/sources.go used a
helper (`getVal`) that did `fmt.Sprint(row[i])` before passing to
`matching.FormatDate`. The Sheets API returns date-formatted cells
as `float64` (Sheets serial-day numbers); pre-stringifying defeated
`FormatDate`'s `case float64:` dispatch, so values like 46147 leaked
through unchanged as the string "46147" instead of being converted
to "2026-05-05".
Surfaced by `make parity` (M5.4) — every `transactions[].date` on
/api/adults and /api/juniors differed between Python and Go. Python
side passes the raw value through directly (`isinstance(val, (int,
float))` in scripts/match_payments.py format_date), so it was always
correct.
Added a `getRaw` helper that returns row[i] without stringifying;
only the date column needs it. Extended TestLoadTransactions with
a numeric-serial-day row to lock in the regression.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds cmd/parity/main.go: a standalone Go binary that GETs
/api/version, /api/adults, /api/juniors, /api/payments from both
the Python (:5001) and Go (:8080) backends, scrubs an allowlist
(render_time.total, build_meta), and prints cmp.Diff for any
remaining differences. Exits 0 on full match, 1 on diffs, 2 on
fetch/parse errors — CI-friendly for M7.2.
- go/cmd/parity/main.go: flags (-py, -go, -route, -timeout), fetch
helper, allowlist scrubber (dotted-path aware), exit-code logic.
- go/cmd/parity/scrub_test.go: 4 unit tests for the scrubber.
- go/go.mod: promote github.com/google/go-cmp to direct dep.
- Makefile: parity target + help entry.
- Progress tracker: M5.4 ticked; milestone updated to M5 complete.
- Plan archived to docs/plans/2026-05-07-2254-m5-4-parity-binary.md.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Previously both backends defaulted to `CacheDir=tmp` and used the
same cache keys (`attendance_regular`, `attendance_juniors`,
`payments_transactions`, `exceptions_dict`) but stored different
shapes: Python caches post-processed view-model tuples
(e.g. `(members, sorted_months)`), Go caches raw sheet rows.
Whichever backend wrote last poisoned the cache for the other,
producing `ValueError: too many values to unpack (expected 2,
got 68)` on Python's /adults after the Go side populated the
file with 68 raw CSV rows.
This breaks the M5.4 `make parity` workflow that requires both
backends running side-by-side.
Fix: change Go's default to `tmp/go` so the two cache trees
never overlap. `CACHE_DIR` env var override still works.
`os.MkdirAll` already handles creating the new subdirectory on
first write.
Recovery for users with poisoned `tmp/`: hit /flush-cache on
the Python side once after pulling, then restart the Go server.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Add internal/web/api package with Go structs for every /api/X route:
AdultsResponse, JuniorsResponse, PaymentsResponse, VersionResponse.
All fields carry explicit json: tags matching the Python view-model keys.
Key design choices:
- member_data / month_labels / raw_payments are nested objects (not
the pre-serialised JSON strings used in Jinja templates)
- Expected{Value int; Unknown bool} with custom MarshalJSON emits int
or the string "?" for junior single-attendance months
- RawTransaction covers the full 11-column payments sheet row
schemagen_test.go reflects all four response types via
github.com/invopop/jsonschema and golden-compares against committed
schemas in tests/fixtures/api-schema/. The JSONSchema() method on
Expected lives in the test file so the prod binary has no jsonschema
dependency.
Closes M5.1 in docs/plans/2026-05-03-2349-go-backend-rewrite-progress.md.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Fio's transparent account page now serves dates as DD.MM.YY (e.g.
07.05.26) rather than the previously expected 4-digit-year format.
Extends parseCzechDate to try all eight layout variants: padded and
non-padded, dot and slash separators, 4-digit and 2-digit years.
Go maps 2-digit year 00-68 → 2000-2068, so 26 → 2026.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Wires slog.SetDefault to honour LOG_LEVEL in all CLI commands and adds
debug logs on the Fio fetch path so a silent "fetched 0 transaction(s)"
can be diagnosed without code changes:
- fio.New: which client variant (api/transparent) was selected
- apiClient: GET URL (token redacted as ****), HTTP status, body bytes,
parsed transaction count
- transparentClient: GET URL, HTTP status, body bytes, plus parser
stats (raw rows from second table, kept, dropped_bad_date,
dropped_nonpositive_amount)
Also suppresses the --print-fio-table block when zero transactions were
fetched, so the bare header no longer prints under that condition.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Prints an aligned tabwriter table of every Fio transaction in the
look-back window, with a STATUS column showing NEW (would be appended)
or DUP (already in sheet). Only fires when --dry-run is also set, so
it can't affect real syncs. Refactors Sync ID computation into a single
pre-pass shared by both the table printer and the row builder.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
extractSecondTableRows tracked a boolean inTarget flag and exited on
the first </table> token while inside the target. Any nested <table>
(e.g. pagination markup in the real Fio page) would cause an early
return before reading any data rows, explaining the 0-transaction report.
Fixed by tracking targetDepth instead: depth increments on every <table>
inside the target and we only return when it reaches 0 again.
parseCzechDate also only tried zero-padded layouts ("02.01.2006").
The real Fio transparent page emits non-padded dates ("7.5.2026");
added "2.1.2006" and "2/1/2006" as the preferred layouts.
Also adds a dry-run diagnostic line ("fetched N transaction(s) from Fio")
so the fetch vs dedup split is visible without reading logs.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
When token is empty, New falls back to transparentClient with the
caller-supplied hc. main.go passes nil, so the first Do() call panicked.
Default to http.DefaultClient when hc is nil.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Mirror fuj infer's read-only mode: SyncOpts.DryRun skips WriteHeader,
AppendValues, and SortByDateColumn, printing one "Dry run: would …"
line per planned operation instead. ID-dedup still runs so the output
reflects exactly what the next real sync would write.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes M3.1–M3.6. Parity safety net proving Go output matches Python
for every ported pure-domain function (M2.1–M2.9) and reconcile (M2.10).
Capture pipeline:
- scripts/capture_fixtures.py: calls each Python function with seeded
inputs, emits JSON fixtures to stdout (never writes files directly).
- scripts/scrub_fixtures.py: deterministic PII scrubber — SHA-256
pseudonyms for member names, digit-preserving hashes for VS/account/
bank_id, name-sweep in message text. Idempotent; no salt.
- scripts/_fixture_seeds.py: handcrafted seeds for all 11 functions;
synthetic names throughout (no real roster members).
- scripts/capture_all_fixtures.sh: convenience wrapper for full corpus
regeneration outside of make.
Fixture corpus (98 files, all PII-free):
- go/tests/fixtures/pure/<func>/<case>.json — 10 function directories.
- go/tests/fixtures/reconcile/<NN>_<case>.json — 10 branch-coverage
cases: greedy, overpayment credit, proportional remainder, even-split,
out-of-window, exception override, other: purpose, junior ?, multi-
person+month fan-out, unmatched.
Go parity tests (//go:build parity):
- go/tests/parity/parityio.go: generic LoadDir/RunAll helpers + typed
In/Out struct pairs for all 10 pure functions; Envelope decoder for
int/float/none disambiguation.
- 10 pure-function test packages + bespoke reconcile test with per-cell
float tolerance (math.Abs <= 0.01 for `paid` values).
Makefile: go-parity, go-test-all, capture-fixtures targets.
go/tests/fixtures/README.md: refresh workflow + PII audit guide.
Gate: make go-test green, make go-parity green (11/11 packages),
make go-lint clean (parity tag), make go-build clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Add internal/services/membership package: AttendanceLoader,
TransactionLoader, ExceptionLoader interfaces + NewStubSources stub
(returns ErrIOPending until M4 lands real Sheets loaders).
FeesReport and ReconcileReport orchestrate domain/fees + domain/reconcile
and write fixed-width text reports matching Python calculate_fees.py and
match_payments.py print_report output. 13 unit tests cover all formatter
branches and orchestration wiring via fake loaders.
cmd/fuj/main.go: fees and reconcile subcommands now dispatch; sync/infer
retain the [M4] placeholder.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
New go/internal/domain/matching package porting three helpers from
scripts/match_payments.py:
- BuildNameVariants: normalized ASCII variants from a member name (nickname
in parens, last/first split, len<3 filtered); variants[0] is always the
full base name — MatchMembers relies on this invariant.
- MatchMembers: auto/review confidence matching with an exact-name
short-circuit pass that prevents nickname substrings (tov) from firing
inside longer surnames (ottova); common-surname filter for review tier.
- FormatDate: nil/empty/""/serial int/float64 (since 1899-12-30, fractional
days supported)/YYYY-MM-DD passthrough/garbage → never errors.
- InferTransactionDetails: composes BuildNameVariants+MatchMembers+
ParseMonthReferences; falls back to sender-only member match and
date-derived month when text carries no signal.
21 table-driven tests; all expected values verified against live Python
on 2026-05-06. go-build, go-test, go-lint all clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
SHA-256 dedup hash from sync_fio_to_sheets.py generate_sync_id.
Key subtlety: Python str(float) emits "500.0" for whole-valued floats
and switches to scientific notation at |f|>=1e16 or |f|<1e-4 —
replicated via formatAmount using 'f'/'e' format selection.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Port scripts/infer_payments.py parse_czk_amount to Go as
internal/domain/money.ParseCZK. Preserves the Czech-locale heuristic
(comma = decimal sep; 2+ dots = thousand seps; single dot = decimal)
and returns (float64, error) so callers can opt into Python's
silent-zero contract via v, _ := money.ParseCZK(s).
All expected values verified against live Python on 2026-05-06.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Ports calculate_fee and calculate_junior_fee from scripts/attendance.py
into a new go/internal/domain/fees package. Introduces the Expected type
(Value int, Unknown bool) for the junior "?" sentinel, keeping the Go
API strictly typed instead of mirroring Python's str|int return.
All 20 table-driven tests pass with -race; golangci-lint clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Three-pass regex parser matching python/czech_utils.py parse_month_references:
1. Numeric slash notation — "11+12/2025", "01/26"; 2-digit year → +2000
2. Dot notation — "12.2025" (4-digit year only)
3. Czech month names — range walk (listopad-leden wrap logic) then
standalone with m≥10 → defaultYear-1 heuristic; longest-match
alternation (sorted desc by name length) handles cervenec vs cerven
35 table-driven tests, all expected outputs verified against live Python
on 2026-05-05 before locking. Plan at
docs/plans/2026-05-05-2337-go-rewrite-m2-2-parse-month-references.md.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds internal/domain/czech.Normalize, the first pure-domain function in
the Go rewrite (M2 milestone). Matches Python czech_utils.normalize byte-
for-byte: NFKD decompose via golang.org/x/text/unicode/norm, drop Mn-
category combining marks (unicode.Mn, not IsMark, to match Python's
unicodedata.combining() semantics), then strings.ToLower.
Includes 13-case table-driven test; all inputs spot-checked against the
Python implementation before locking. Adds golang.org/x/text v0.36.0 as
first external dependency.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
kacerrandClaude Opus 5.5