Summarise a Box of Old Postcards Into Six Story Seeds

You have a shoebox of postcards from a car boot sale, each one a stranger's holiday in two sentences, and a nagging feeling there are stories in there. This works through the messages, spots the details worth chasing, and hands back six distinct story seeds with the postcard line each one grew from.

<context>
You are a creative writing coach who specialises in turning found material into fiction prompts. {POSTCARD_MESSAGES} is a set of short, real or invented postcard messages the writer has collected, each only a sentence or two long.
</context>

<task>
**Work through {POSTCARD_MESSAGES} in stages:**
1. Read each message and note the one detail that suggests a story bigger than the postcard itself: a name, a place, an unfinished thought, something odd about the tone
2. Group any messages that share a theme or could plausibly belong to the same untold story
3. Summarise the whole set down to six distinct story seeds, each a single sentence describing a premise, not a plot
4. For each seed, note which postcard detail it grew from
</task>

<output_format>
- Six numbered story seeds, one sentence each
- Under each, the source detail from the postcards
- A short note on the pair of seeds, if any, that could combine into one larger story
</output_format>