feat: 3 new tools, format streaming, distribution-ready demo + landing pages

Tools shipped this batch (4 → 6 of 9 Ready):
  04 Missing Value Handler   src/core/missing.py + cli_missing.py + GUI
  05 Column Mapper           src/core/column_mapper.py + cli_column_map.py + GUI
  09 Pipeline Runner         src/core/pipeline.py + cli_pipeline.py + GUI
                             with soft tool-dependency graph (recommended,
                             not enforced) and JSON save/load for repeatable
                             weekly cleanups.

Format Standardizer reworked for 1 GB international files:
  • Vectorised dispatch + LRU cache over phone/date/currency/boolean/email
  • Per-row country / address columns drive parsing
  • Audit cap (default 10 k rows, ~50 MB RAM)
  • standardize_file(): chunked streaming entry point (~165 k rows/sec)
  • currency_decimal="auto" for EU comma-decimal locales
  • R$ / kr / zł multi-char currency prefixes
  • cli_format.py with auto-stream above 100 MB inputs

Encoding detection arbiter + language-aware probe:
  Closes the last 4 xfails (cp1250 / mac_iceland / shift_jis_2004 / lying-BOM)
  via tied-confidence arbiter + Cyrillic / EE-Latin coverage probes.

Distribution-readiness assets:
  • streamlit_app.py — Streamlit Community Cloud entry shim
  • src/gui/app_demo.py — single-page demo, ?p=<persona> routing,
    100-row cap + watermark, free-vs-paid boundary enforced at surface
  • samples/demo/ — 3 niche datasets + pre-tuned pipeline JSONs
  • landing/ — 4 static HTML pages (apex chooser + 3 niche),
    shared CSS, deploy.py URL-substitution script,
    auto-generated robots.txt + sitemap.xml + 404.html + favicon
  • docs/PLAN.md, DEMO-PLAN.md, DEPLOYMENT.md, POST-LAUNCH.md, NEXT-STEPS.md
    — full strategy + measurement + deployment + master checklist

Test counts:
  before: 1,520 passed · 4 skipped · 17 xfailed
  after:  1,729 passed · 0 skipped · 0  xfailed

Tier-1 corpora added:
  • missing-corpus           3 use cases + 16 edge cases
  • column-mapper-corpus     3 use cases + 5 edge cases
  • format-cleaner intl      20-row 13-country stress fixture

Engine hardening flushed out by the corpora:
  • interpolate guards against object-dtype columns
  • mean/median skip all-NaN columns (silences numpy warning)
  • fillna runs under future.no_silent_downcasting (silences pandas warning)
  • mojibake test no longer skips when ftfy installed (monkeypatch path)
  • drop-row threshold semantics: strict-greater (consistent across rows / cols)
  • currency_decimal validator allow-set updated for "auto"

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test-cases/missing-corpus/README.md

@@ -0,0 +1,35 @@
+# Missing Value Handler — corpus
+
+Acceptance fixtures for `src/core/missing.py`. Each `.csv` under
+`test_data/` is paired with assertions in `tests/test_missing_corpus.py`.
+Add a new case by dropping a CSV here and adding a parametrize entry to
+the runner.
+
+## Use cases (target client profiles)
+
+| File | Buyer profile | Strategy under test |
+|------|---------------|---------------------|
+| `uc01_shopify_export.csv`     | SMB / Shopify operator    | `detect-only`       |
+| `uc02_marketing_audience.csv` | Marketing / RevOps analyst| `safe-fill`         |
+| `uc03_consultant_intake.csv`  | Analyst / consultant      | `drop-incomplete` + threshold |
+
+## Edge cases
+
+| File | What it stresses |
+|------|------------------|
+| `ec01_all_nan_column.csv`         | column 100 % missing — fill must skip, drop_col must catch at threshold |
+| `ec02_no_missing.csv`             | clean file — must be a no-op |
+| `ec03_zero_is_not_missing.csv`    | numeric `0`, boolean `false`, `"0"` must NOT be treated as missing |
+| `ec04_excel_errors.csv`           | `#N/A`, `#NULL!`, `#VALUE!` Excel error sentinels |
+| `ec05_unicode_whitespace.csv`     | NBSP, tab-only, ideographic-space cells treated as whitespace |
+| `ec06_mixed_dtypes.csv`           | mixed numeric/string in same column — graceful degrade to mode |
+| `ec07_real_data_with_padding.csv` | leading/trailing whitespace around real data must NOT be dropped |
+| `ec08_single_row.csv`             | one-row file — every operation must still work |
+| `ec09_single_column.csv`          | one-column file with header-only line + sentinels |
+| `ec10_all_sentinel_variants.csv`  | every `DEFAULT_SENTINELS` entry exercised in one file |
+| `ec11_constant_per_column.csv`    | `column_fill_values` differs per column |
+| `ec12_drop_threshold_boundary.csv`| boundary values for `row_drop_threshold` (0.5, 0.99, 1.0) |
+| `ec13_ffill_leading_nan.csv`      | leading-NaN run survives ffill (no fabrication) |
+| `ec14_interpolate_fallback.csv`   | numeric-only strategy on string column triggers fallback |
+| `ec15_headers_only.csv`           | empty body — must not crash |
+| `ec16_idempotent_apply.csv`       | running `handle_missing` twice yields the same DataFrame |

test-cases/missing-corpus/test_data/ec01_all_nan_column.csv

@@ -0,0 +1,5 @@
+id,name,deprecated_field
+1,Alice,
+2,Bob,
+3,Charlie,
+4,Diana,

test-cases/missing-corpus/test_data/ec02_no_missing.csv

@@ -0,0 +1,4 @@
+id,name,age,city
+1,Alice,30,NYC
+2,Bob,25,LA
+3,Charlie,35,SF

test-cases/missing-corpus/test_data/ec03_zero_is_not_missing.csv

@@ -0,0 +1,5 @@
+id,active,balance,count,flag
+1,true,0.00,0,0
+2,false,150.50,3,1
+3,true,0,5,0
+4,true,75.25,0,1

test-cases/missing-corpus/test_data/ec04_excel_errors.csv

@@ -0,0 +1,7 @@
+sku,price,units,supplier
+A-100,19.99,5,Acme
+A-101,#N/A,3,Beta
+A-102,29.99,#NULL!,Gamma
+A-103,#VALUE!,2,Delta
+A-104,9.99,0,Acme
+A-105,#N/A,#N/A,#NULL!

test-cases/missing-corpus/test_data/ec05_unicode_whitespace.csv

@@ -0,0 +1,6 @@
+id,note,value
+1,hello,10
+2, ,20
+3,	,30
+4,real,40
+5,　,50

test-cases/missing-corpus/test_data/ec06_mixed_dtypes.csv

@@ -0,0 +1,6 @@
+id,mixed_col,real_num
+1,42,1.0
+2,N/A,2.0
+3,hello,
+4,,4.0
+5,99,5.0

test-cases/missing-corpus/test_data/ec07_real_data_with_padding.csv

@@ -0,0 +1,5 @@
+id,name,city
+1,  Alice  ,NYC
+2,  ,LA
+3, Bob ,
+4,Charlie,  SF

test-cases/missing-corpus/test_data/ec08_single_row.csv

@@ -0,0 +1,2 @@
+id,name,age,city
+1,Alice,N/A,

test-cases/missing-corpus/test_data/ec09_single_column.csv

@@ -0,0 +1,7 @@
+value
+10
+N/A
+20
+" "
+-
+30

test-cases/missing-corpus/test_data/ec10_all_sentinel_variants.csv

@@ -0,0 +1,22 @@
+case_id,sentinel_value
+01,N/A
+02,n/a
+03,NA
+04,na
+05,NULL
+06,null
+07,None
+08,nil
+09,NaN
+10,-
+11,--
+12,?
+13,.
+14,TBD
+15,unknown
+16,(blank)
+17,(none)
+18,#N/A
+19,#NULL!
+20,missing
+21,real_value

test-cases/missing-corpus/test_data/ec11_constant_per_column.csv

@@ -0,0 +1,6 @@
+id,country,salary,department
+1,USA,50000,Eng
+2,,60000,Sales
+3,UK,,Eng
+4,USA,55000,
+5,,,

test-cases/missing-corpus/test_data/ec12_drop_threshold_boundary.csv

@@ -0,0 +1,6 @@
+id,a,b,c,d
+1,1,2,3,4
+2,,,3,4
+3,,,,4
+4,,,,
+5,1,2,,

test-cases/missing-corpus/test_data/ec13_ffill_leading_nan.csv

@@ -0,0 +1,8 @@
+date,price
+2025-01-01,
+2025-01-02,
+2025-01-03,100.0
+2025-01-04,
+2025-01-05,
+2025-01-06,150.0
+2025-01-07,

test-cases/missing-corpus/test_data/ec14_interpolate_fallback.csv

@@ -0,0 +1,6 @@
+id,category,value
+1,A,10.0
+2,B,
+3,C,30.0
+4,,40.0
+5,A,

test-cases/missing-corpus/test_data/ec15_headers_only.csv

@@ -0,0 +1 @@
+id,name,age,city

test-cases/missing-corpus/test_data/ec16_idempotent_apply.csv

@@ -0,0 +1,5 @@
+id,name,age
+1,Alice,30
+2,N/A,
+3,Bob,25
+4,,40

test-cases/missing-corpus/test_data/uc01_shopify_export.csv

@@ -0,0 +1,11 @@
+customer_id,first_name,last_name,email,phone,city,total_orders,lifetime_value,last_order_date,tags
+SHOP-001,Alice,Johnson,alice@shop.com,555-1234,Brooklyn,12,1240.50,2025-12-04,VIP
+SHOP-002,Bob,Smith,bob@shop.com,N/A,Queens,5,420.00,2025-11-22,
+SHOP-003,Carlos,Garcia,carlos@shop.com,555-5678,-,8,890.25,2025-12-15,Wholesale
+SHOP-004,Diana,Lee,diana@shop.com,(555) 222-3344,Manhattan,NULL,1875.00,2025-10-30,VIP|Wholesale
+SHOP-005,Eve,Martinez,,555-9988,Bronx,3,180.00,2025-09-15,
+SHOP-006,Frank,Brown,frank@shop.com, ,Staten Island,15,2410.75,(blank),
+SHOP-007,Grace,Davis,grace@shop.com,555-1111,Brooklyn,1,49.99,#N/A,New
+SHOP-008,Henry,Wilson,henry@shop.com,n/a,Queens,7,675.00,2025-11-08,VIP
+SHOP-009,Ivy,Chen,ivy@shop.com,555-7777,?,4,320.50,2025-10-12,
+SHOP-010,Jack,Taylor,jack@shop.com,555-4444,Manhattan,(none),520.00,2025-12-01,Wholesale

test-cases/missing-corpus/test_data/uc02_marketing_audience.csv

@@ -0,0 +1,16 @@
+contact_id,email,segment,region,age,ltv,score,last_engagement_days,source,consent
+LEAD-001,a@mkt.com,Enterprise,NA-East,42,12400,87,3,LinkedIn,true
+LEAD-002,b@mkt.com,SMB,NA-West,,3200,62,12,Google,true
+LEAD-003,c@mkt.com,SMB,EU,29,1800,N/A,7,unknown,true
+LEAD-004,d@mkt.com,Enterprise,NA-East,55,,91,1,Webinar,true
+LEAD-005,e@mkt.com,Mid-Market,NA-West,38,5600,74,,Referral,true
+LEAD-006,f@mkt.com,SMB,EU,,2100,55,21,-,
+LEAD-007,g@mkt.com,Enterprise,APAC,47,9800,82,5,LinkedIn,true
+LEAD-008,h@mkt.com,SMB,NA-East,33,2900,,9,Google,
+LEAD-009,i@mkt.com,Mid-Market,EU,41,4750,68,15,NULL,true
+LEAD-010,j@mkt.com,Enterprise,NA-West,,11200,89,2,Webinar,true
+LEAD-011,k@mkt.com,SMB,APAC,28,1650,58,18,(blank),true
+LEAD-012,l@mkt.com,Mid-Market,NA-East,36,5100,,11,Referral,true
+LEAD-013,m@mkt.com,SMB,EU,31,2300,61,N/A,Google,true
+LEAD-014,n@mkt.com,Enterprise,APAC,52,10500,93,4,LinkedIn,true
+LEAD-015,o@mkt.com,SMB,NA-West,26,1400,49,25,?,

test-cases/missing-corpus/test_data/uc03_consultant_intake.csv

@@ -0,0 +1,13 @@
+respondent_id,age,gender,zip,survey_q1,survey_q2,survey_q3,survey_q4,nps,comments,internal_id_legacy,beta_field
+R-001,34,F,11201,4,5,3,4,9,"loved it",,
+R-002,N/A,M,10001,,,,, ,,,
+R-003,41,F,90210,5,4,5,5,10,"perfect",,
+R-004,28,M,-,3,,,,7,,,
+R-005,,,NULL,,,,,,,,
+R-006,52,F,02101,4,4,4,4,8,"good experience",,
+R-007,?,?,?,?,?,?,?,?,?,,
+R-008,29,M,94102,5,5,5,5,10,"amazing",,
+R-009,38,F,60601,2,3,2,2,5,"meh",,
+R-010,(blank),(blank),(blank),(blank),(blank),(blank),(blank),(blank),(blank),,
+R-011,45,M,30301,4,4,3,4,8,,,
+R-012,33,F,11201,5,5,5,4,9,"will recommend",,