In `@SQL/Leetcode/Intermediate` Join/1174. Immediate Food Delivery II/Claude
Sonnet 4.5 Extended/Immediate_Food_Delivery_II_pandas.md:
- Around line 92-96: The current selection of first_orders using a min-based
filter can include multiple rows per customer when a customer has tied minimal
order_date; instead, ensure only one "first" order per customer is counted by
switching to the idxmin() approach (use the index of the per-customer minimum
order_date to select a single row) or by deduping the resulting first_orders
with drop_duplicates(subset=['customer_id', 'order_date']) before computing
is_immediate; update the logic around first_orders and the subsequent
is_immediate/percentage computation to reference the single-row-per-customer
result (look for first_orders, transform('min'), idxmin(), and is_immediate in
the diff).
- Line 51: The calculation for percentage can divide by zero when
len(is_immediate) == 0; update the logic around the percentage assignment
(variable percentage) to guard against an empty series/DataFrame (is_immediate)
by checking is_immediate.empty (or len(is_immediate) == 0) and setting
percentage to a safe value (e.g., 0.0 or float('nan')) otherwise perform the
existing calculation rounded to 2 decimals; modify the block that computes
percentage to include this conditional guard referencing percentage and
is_immediate.
- Line 66: The code mutates the input DataFrame by assigning delivery['rn']
which causes side effects; instead compute the rank without modifying the
original by either operating on a copy of delivery or using DataFrame.assign to
produce a new DataFrame (e.g., create a new variable from
delivery.assign(rn=...) and then filter where rn == 1), referencing the same
grouping by 'customer_id' and ranking on 'order_date' so all logic
(groupby('customer_id')['order_date'].rank(method='first', ascending=True))
remains but never writes back into the original delivery object.

In `@SQL/Leetcode/Intermediate` Join/1174. Immediate Food Delivery II/Claude
Sonnet 4.5 Extended/Immediate_Food_Delivery_II_postgre.md:
- Around line 63-69: The AVG-based expression can return NULL when first_orders
has no rows, so wrap the aggregation in COALESCE to return 0.0 instead;
specifically update the SELECT that computes immediate_percentage (ROUND(100.0 *
AVG(is_immediate::int), 2) AS immediate_percentage) to use
COALESCE(AVG(is_immediate::int), 0.0) so the query yields 0.00 instead of NULL
for empty result sets.
- Around line 37-44: The query that computes immediate_percentage can return
NULL when the table is empty; update the SELECT that references SUM(CASE...) /
COUNT(*) (the immediate_percentage expression that queries first_orders filtered
by rn = 1) to explicitly handle NULL/zero by wrapping the whole ROUND(...)
expression with COALESCE(..., 0.0) (or otherwise check COUNT(*) = 0) so the
query returns 0.0 instead of NULL for empty result sets.

In @.agent/workflows/svg_flowchart_guidelines.md:
- Around line 19-23: The fenced code block containing "viewBox height =
header_height + (row_count × row_height) + summary_text_spacing + padding"
violates MD031; add a blank line immediately before the opening ``` and a blank
line immediately after the closing ``` so the fence is separated from
surrounding text (update the markdown around that fenced block in
svg_flowchart_guidelines.md).

In `@SQL/Leetcode/Intermediate` Join/1174. Immediate Food Delivery II/Claude
Sonnet 4.5 Extended/Immediate_Food_Delivery_II_postgre.md:
- Around line 88-93: Guard against division-by-zero when computing
immediate_percentage: replace the denominator COUNT(*) in the ROUND expression
with NULLIF(COUNT(*), 0) and wrap the whole division with COALESCE(..., 0) so
the query on first_orders returns 0.00 when the table is empty; update the
expression that uses ROUND and COUNT(*) FILTER (WHERE is_immediate) accordingly.

In `@SQL/Leetcode/Intermediate` Join/1174. Immediate Food Delivery II/Claude
Sonnet 4.5 Extended/Immediate_Food_Delivery_II_postgre.md:
- Around line 88-96: The COALESCE fallback value is formatted
inconsistently—change the literal in the SELECT that defines
immediate_percentage from 0.00 to 0.0 so numeric-literal formatting matches the
earlier 0.0 usage; update the COALESCE(...) AS immediate_percentage expression
that uses NULLIF(COUNT(*), 0) and COUNT(*) FILTER (WHERE is_immediate) to return
0.0 instead of 0.00.